Humanized anti-cd22 antibodies and their use in treatment of oncology, transplantation and autoimmune disease

ABSTRACT

The present invention provides chimeric and humanized versions of anti-CD22 mouse monoclonal antibody, HB22.7. The anti-CD22 antibodies of the invention comprise four human or humanized framework regions of the immunoglobulin heavy chain variable region (“VH”) and four human or humanized framework regions of the immunoglobulin light chain variable region (“VK”). The invention further comprises heavy and/or light chain FW regions that contain one or more backmutations in which a human FW residue is exchanged for the corresponding residue present in the parental mouse heavy or light chain. Human or humanized VH framework regions of antibodies of the invention may comprise one or more of the following residues: a valine (V) at position 24 of framework region 1, a glycine (G) at position 49 of framework region 2, and an asparagine (N) at position 73 of framework region 3, numbered according to Kabat. The invention further relates to pharmaceutical compositions, immunotherapeutic compositions, and methods using therapeutic antibodies that bind to the human CD22 antigen and that preferably mediate human ADCC, CDC, and/or apoptosis for: the treatment of B cell diseases and disorders in human subjects, such as, but not limited to, B cell malignancies, for the treatment and prevention of autoimmune disease, and for the treatment and prevention of graft-versus-host disease (GVHD), humoral rejection, and post-transplantation lymphoproliferative disorder in human transplant recipients.

This application is a divisional of U.S. application Ser. No.11/715,308, filed on Mar. 6, 2007, which claims priority benefit under35 U.S.C. §119(e) to U.S. Provisional Application No. 60/779,806 (filedon Mar. 6, 2006), each of which is incorporated by reference herein inits entirety.

One or more inventions disclosed herein were made, in part, withgovernment support under contract number N01-CO-12400 awarded by theNational Cancer Institute, National Institutes of Health. The UnitedStates Government has certain rights in one or more of thepresently-disclosed inventions.

1. INTRODUCTION

The present invention relates to human, humanized, or chimeric anti-CD22antibodies that bind to the human CD22 antigen. The present invention isalso directed to compositions comprising human, humanized, or chimericanti-CD22 antibodies that mediate one or more of the following:complement-dependent cell-mediated cytotoxicity (CDC),antibody-dependent cell-mediated cytotoxicity (ADCC), and programmedcell death (apoptosis). The present invention is further directed tocompositions comprising human, humanized, or chimeric anti-CD22antibodies of the IgG1 and/or IgG3 human isotype, as well as tocompositions comprising human, humanized, or chimeric anti-CD22antibodies of the IgG2 and/or IgG4 human isotype that preferably mediatehuman ADCC, CDC, or apoptosis.

The present invention is further directed to methods for the treatmentof B cell disorders or diseases in human subjects, including B cellmalignancies, using the therapeutic human, humanized, or chimericanti-CD22 antibodies that bind to the human CD22 antigen. The presentinvention is directed to methods for the treatment and prevention ofautoimmune disease as well as the treatment and prevention ofgraft-versus-host disease (GVHD), humoral rejection, andpost-transplantation lymphoproliferative disorder in human transplantrecipients using the therapeutic human, humanized, or chimeric anti-CD22antibodies of the invention that bind to the human CD22 antigen.

2. BACKGROUND OF THE INVENTION

The proliferation and differentiation of B cells is a complex processdirected and regulated through interactions with many other cell types.In this context, B cell surface markers have been generally suggested astargets for the treatment of B cell disorders or diseases, autoimmunedisease, and transplantation rejection. Examples of B cell surfacemarkers include CD10, CD19, CD20, CD21, CD22, CD23, CD24, CD37, CD53,CD72, CD74, CD75, CD77, CD79a, CD79b, CD80, CD81, CD82, CD83, CD84,CD85, and CD86 leukocyte surface markers. Antibodies that specificallybind these markers have been developed, and some have been tested forthe treatment of diseases and disorders.

For example, chimeric or radiolabeled monoclonal antibody (mAb)-basedtherapies directed against the CD20 cell surface molecule specific formature B cells and their malignant counterparts have been shown to be aneffective in vivo treatment for non-Hodgkin's lymphoma (Tedder et al.,Immunol. Today 15:450-454 (1994); Press et al., Hematology: 221-240(2001); Kaminski et al., N. Engl. J. Med. 329:459-465 (1993); Weiner,Semin. Oncol. 26:43-51 (1999); Onrust et al., Drugs 58:79-88 (1999);McLaughlin et al., Oncology 12:1763-1769 (1998); Reff et al., Blood83:435-445 (1994); Maloney et al., Blood 90:2188-2195 (1997); Malone etal., J. Clin. Oncol. 15:3266-3274 (1997); Anderson et al., Biochem. Soc.Transac. 25:705-708 (1997)). Anti-CD20 monoclonal antibody therapy hasalso been found to be partially effective in attenuating themanifestations of rheumatoid arthritis, systemic lupus erythematosus,idiopathic thrombocytopenic purpura and hemolytic anemia, as well asother immune-mediated diseases (Silverman et al., Arthritis Rheum.48:1484-1492 (2002); Edwards et al., Rheumatology 40:1-7 (2001); De Vitaet al., Arthritis Rheumatism 46:2029-2033 (2002); Leandro et al., Ann.Rheum. Dis. 61:883-888 (2002); Leandro et al., Arthritis Rheum.46:2673-2677 (2001)). The anti-CD20 (IgG1) antibody, RITUXAN™, hassuccessfully been used in the treatment of certain diseases such asadult immune thrombocytopenic purpura, rheumatoid arthritis, andautoimmune hemolytic anemia (Cured et al., WO 00/67796). Despite theeffectiveness of these therapies, B cell depletion is less effectivewhere B cells do not express or express CD20 at low levels, (e.g., onpre-B cells or immature B cells) or have lost CD20 expression followingCD20 immunotherapy (Smith et al., Oncogene 22:7359-7368 (2003)).

Anti-CD22 antibodies have been described, for example, in U.S. Pat. Nos.5,484,892; 6,183,744; 6,187,287; 6,254,868; 6,306,393, and in Tuscano etal., Blood 94(4):1382-92 (1999) (each of which is incorporated herein inits entirety by reference). The use of monoclonal antibodies, includinganti-CD22 antibodies, in the treatment of non-Hodgkin's lymphoma isreviewed, for example, by Renner et al., Leukemia 11 (Suppl. 2):S5509(1997).

The use of humanized CD22 antibodies has been described for thetreatment of autoimmune disorders (see, Tedder U.S. Patent ApplicationPublication No. US2003/0202975) and for the treatment of B cellmalignancies, such as lymphomas and leukemia (see, Tuscano U.S. PatentApplication Publication No. U.S. 2004/0001828). Humanized CD22antibodies that target specific epitopes on CD22 have been described foruse in immunoconjugates for therapeutic uses in cancer (see U.S. Pat.Nos. 5,789,554 and 6,187,287 to Leung).

Epratuzumab (LymoCide™ Immunomedics, Inc.), a humanized version of themurine LL2, is under development for the treatment of non-Hodgkin'slymphomas (Coleman, Clin. Cancer Res. 9:39915-45 (2003)). ADOTA-conjugated ⁹⁰Y-radiolabeled form of Epratuzumab is currently inPhase III clinical trials for the treatment of indolent and aggressiveforms of non-Hodgkin's lymphomas (Linden et al., Clin Cancer Res II(14):5215-5222 (2005)). Epratuzumab in combination with Rituximab iscurrently in Phase II clinical trials for the same indication.

Despite recent advances in cancer therapy, B cell malignancies, such asthe B cell subtypes of non-Hodgkin's lymphomas, and chronic lymphocyticleukemia, are major contributors of cancer-related deaths. Accordingly,there is a great need for further, improved therapeutic regimens for thetreatment of B cell malignancies.

Both cellular (T cell-mediated) and humoral (antibody, B cell-mediated)immunity are now known to play significant roles in graft rejection.While the importance of T cell-mediated immunity in graft rejection iswell established, the critical role of humoral immunity in acute andchronic rejection has only recently become evident. Consequently, mostof the advances in the treatment and prevention of graft rejection havedeveloped from therapeutic agents that target T cell activation. Thefirst therapeutic monoclonal antibody that was FDA approved for thetreatment of graft rejection was the murine monoclonal antibodyORTHOCLONE-OKT3™ (muromonab-CD3), directed against the CD3 receptor of Tcells. OKT3 has been joined by a number of other anti-lymphocytedirected antibodies, including the monoclonal anti-CD52 CAMPATH™antibodies, CAMPATH-1G, CAMPATH-1H (alemtuzumab), and CAMPATH-1M), andpolyclonal anti-thymocyte antibody preparations (referred to asanti-thymocyte globulin, or “ATG,” also called “thymoglobin” or“thymoglobulin”). Other T cell antibodies approved for the prevention oftransplant rejection include the chimeric monoclonal antibody SIMULECT™(basiliximab) and the humanized monoclonal antibody ZENAPAX™(daclizumab), both of which target the high-affinity IL-2 receptor ofactivated T cells.

The importance of humoral immunity in graft rejection was initiallythought to be limited to hyperacute rejection, in which the graftrecipient possesses anti-donor HLA antibodies prior to transplantation,resulting in rapid destruction of the graft in the absence of aneffective therapeutic regimen of antibody suppression. Recently, it hasbecome evident that humoral immunity is also an important factormediating both acute and chronic rejection. For example, clinicalobservations demonstrated that graft survival in patients capable ofdeveloping class I or class II anti-HLA alloantibodies (also referred toas “anti-MHC alloantibodies”) was reduced compared to graft survival inpatients that could not develop such antibodies. Clinical andexperimental data also indicate that other donor-specific alloantibodiesand autoantibodies are critical mediators of rejection. For a currentreview of the evidence supporting a role for donor-specific antibodiesin allograft rejection, see Rifle et al., Transplantation, 79: S114-S18(2005). Thus, due to the relatively recent appreciation of the role ofhumoral immunity in acute and chronic graft rejection, currenttherapeutic agents and strategies for targeting humoral immunity areless well developed than those for targeting cellular immunity.Accordingly, there is a need in the art for improved reagents andmethods for treating and preventing graft rejection, i.e.graft-versus-host disease (GVHD), humoral rejection, andpost-transplantation lymphoproliferative disorder in human transplantrecipients.

Autoimmune diseases as a whole cause significant morbidity anddisability. Based on incidence data collected from 1965 to 1995, it hasbeen estimated that approximately 1.2 million persons will develop a newautoimmune disease over the next five years. Jacobsen et al. (ClinImmunol. Immunopathol. 84:223 (1997)) evaluated over 130 publishedstudies and estimated that in 1996, 8.5 million people in the UnitedStates (3.2% of the population) had at least one of the 24 autoimmunediseases examined in these studies. Considering the major impact ofautoimmune diseases on public health, effective and safe treatments areneeded to address the burden of these disorders. Thus, there is a needin the art for improved reagents and methods for treating autoimmunedisease.

3. SUMMARY OF THE INVENTION

The invention relates to chimeric, human, and humanized anti-CD22monoclonal antibodies that comprise a heavy chain and a light chain,wherein the heavy chain variable region comprises three complementaritydetermining regions, CDR1, CDR2, and CDR3, and four framework regions,FW1, FW2, FW3, and FW4, in the order FW1-CDR1-FW2-CDR2-FW3-CDR3-FW4, andwherein CDR1 comprises the amino acid sequence DYGVN (SEQ ID NO:62),CDR2 comprises the amino acid sequence IIWGDGRTDYNSALKS (SEQ ID NO:63),and CDR3 comprises the amino acid sequence APGNRAMEY (SEQ ID NO:64).

In certain embodiments, FW1 of the heavy chain variable region of themonoclonal antibodies of the present invention comprises the amino acidsequence QVQLQESGPALVKPTQTLTLTCTFSGFSLS (SEQ ID NO:73) orQVQLQESGPALVKPTQTLTLTCTVSGFSLS (SEQ ID NO:74), FW2 comprises the aminoacid sequence WIRQPPGKALEWLA (SEQ ID NO:75) or WIRQPPGKALEWLG (SEQ IDNO:76), FW3 comprises the amino acid sequenceRLSISKDTSKNQVVLRMTNVDPVDTATYFCAR (SEQ ID NO:77) orRLSISKDNSKNQVVLRMTNVDPVDTATYFCAR (SEQ ID NO:78). In a particular aspectof each of theses embodiments, FW4 comprises the amino acid sequenceWGQGTVVTVSS (SEQ ID NO:79).

The present invention is also directed in one aspect to a humanizedanti-CD22 monoclonal antibody in which CDR1 comprises the amino acidsequence DYGVN (SEQ ID NO:62), CDR2 comprises the amino acid sequenceIIWGDGRTDYNSALKS (SEQ ID NO:63), and CDR3 comprises the amino acidsequence APGNRAMEY (SEQ ID NO:64), while FW1 comprises the amino acidsequence QVQLQESGPALVKPTQTLTLTCTVSGFSLS (SEQ ID NO:74), FW2 comprisesthe amino acid sequence WIRQPPGKALEWLG (SEQ ID NO:76), FW3 comprises theamino acid RLSISKDNSKNQVVLRMTNVDPVDTATYFCAR (SEQ ID NO:78), and FW4comprises the amino acid sequence WGQGTVVTVSS (SEQ ID NO:79).

In certain embodiments, FW1 of the heavy chain variable region of themonoclonal antibodies of the present invention comprises the amino acidsequence QVQLEESGGGVVRPGRSLRLSCAASGFTFD (SEQ ID NO:80),QVQLEESGGGVVRPGRSLRLSCAASGFTFS (SEQ ID NO: 81),QVQLEESGGGVVRPGRSLRLSCAASGFTLD (SEQ ID NO:82), orQVQLEESGGGVVRPGRSLRLSCAASGFTLS (SEQ ID NO:83), FW2 comprises an aminoacid sequence WIRQAPGKGLEWVT (SEQ ID NO:84) or WIRQAPGKGLEWVG (SEQ IDNO:85), FW3 comprises the amino acid sequenceRFTVSRNNSNNTLSLQMNSLTTEDTAVYYCVR (SEQ ID NO:86) orRLTVSRNNSNNTLSLQMNSLTTEDTAVYYCVR (SEQ ID NO:87). In a particular aspectof each of theses embodiments, FW4 comprises the amino acid sequenceWGQGVLVTVS (SEQ ID NO:88).

The present invention is further directed in one aspect to a humanizedanti-CD22 monoclonal antibody in which CDR1 comprises the amino acidsequence DYGVN (SEQ ID NO:62), CDR2 comprises the amino acid sequenceIIWGDGRTDYNSALKS (SEQ ID NO:63), and CDR3 comprises the amino acidsequence APGNRAMEY (SEQ ID NO:64), while FW1 comprises the amino acidsequence QVQLEESGGGVVRPGRSLRLSCAASGFTLS (SEQ ID NO:83), FW2 comprisesthe amino acid sequence WIRQAPGKGLEWVG (SEQ ID NO:85), FW3 comprises theamino acid RLTVSRNNSNNTLSLQMNSLTTEDTAVYYCVR (SEQ ID NO:87), and FW4comprises the amino acid sequence WGQGVLVTVS (SEQ ID NO:88).

In still another aspect of this embodiment, the present invention isfurther directed in one aspect to a humanized anti-CD22 monoclonalantibody in which CDR1 comprises the amino acid sequence DYGVN (SEQ IDNO:62), CDR2 comprises the amino acid sequence IIWGDGRTDYNSALKS (SEQ IDNO:63), and CDR3 comprises the amino acid sequence APGNRAMEY (SEQ IDNO:64), while FW1 comprises the amino acid sequenceQVQLEESGGGVVRPGRSLRLSCAASGFTFS (SEQ ID NO:81), FW2 comprises the aminoacid sequence WIRQAPGKGLEWVT (SEQ ID NO:84), FW3 comprises the aminoacid RFTVSRNNSNNTLSLQMNSLTTEDTAVYYCVR (SEQ ID NO:86), and FW4 comprisesthe amino acid sequence WGQGVLVTVS (SEQ ID NO:88).

The humanized anti-CD22 monoclonal antibodies of the present inventionalso include those in which FW3 of the heavy chain variable region ofthe monoclonal antibodies of the present invention comprises the aminoacid sequence of RLIISRDNYKNTMSLQMYSLSAADTAIYFCVK (SEQ ID NO:89),RFNISRDNYKNTMSLQMYSLSAADTAIYFCVK (SEQ ID NO:90),RFIISRDNYKNTNSLQMYSLSAADTAIYFCVK (SEQ ID NO:91),RLNISRDNYKNTMSLQMYSLSAADTAIYFCVK (SEQ ID NO:92),RLIISRDNYKNTNSLQMYSLSAADTAIYFCVK (SEQ ID NO:93),RFNISRDNYKNTNSLQMYSLSAADTAIYFCVK (SEQ ID NO:94), orRLNISRDNYKNTNSLQMYSLSAADTAIYFCVK (SEQ ID NO:95). The humanized anti-CD22monoclonal antibodies of the invention therefore include a humanizedmonoclonal antibody in which the heavy chain variable regions includesFW1 comprises the amino acid sequence EVQLVESGGGLVQPGGSLRLSCAASGFTFS(SEQ ID NO:96), FW2 comprises the amino acid sequence WVRQAPGKGLEWIS(SEQ ID NO:97), FW3 comprises the amino acid sequenceRFIISRDNYKNTMSLQMYSLSAADTAIYFCVK (SEQ ID NO:98), and FW4 comprises theamino acid sequence WGQGTMVTVS (SEQ ID NO:99).

The humanized anti-CD22 monoclonal antibodies of the present inventionalso include those in which FW1 of the heavy chain variable region ofthe monoclonal antibodies of the present invention comprises the aminoacid sequence QVQLEESGGGVVRPGRSLRLSCAASGFTFD (SEQ ID NO:80),QVQLEESGGGVVRPGRSLRLSCAASGFTLD (SEQ ID NO:82),QVQLEESGGGVVRPGRSLRLSCAASGFTFS (SEQ ID NO:81), orQVQLEESGGGVVRPGRSLRLSCAASGFTLS (SEQ ID NO:83); FW2 comprises the aminoacid sequence WIRQAPGKGLEWVT (SEQ ID NO:84) or WIRQAPGKGLEWVG (SEQ IDNO:85); FW3 comprises the amino acid sequenceRFTISRNNSNNTLSLQMNSLTTEDTAVYYCVR (SEQ ID NO:100) orRLTISRNNSNNTLSLQMNSLTTEDTAVYYCVR (SEQ ID NO:101). In a particular aspectof each of theses embodiments, FW4 comprises the amino acid sequenceWGQGVLVTVS (SEQ ID NO:88).

The humanized anti-CD22 monoclonal antibodies of the invention thereforeinclude a humanized monoclonal antibody in which the heavy chainvariable region includes framework regions in which FW1 comprises theamino acid sequence QVQLEESGGGVVRPGRSLRLSCAASGFTFS (SEQ ID NO:81), FW2comprises the amino acid sequence WIRQAPGKGLEWVT (SEQ ID NO:84), FW3comprises the amino acid sequence RFTISRNNSNNTLSLQMNSLTTEDTAVYYCVR (SEQID NO:100), and FW4 comprises the amino acid sequence WGQGVLVTVS (SEQ IDNO:88).

The humanized anti-CD22 monoclonal antibodies of the present inventionalso include those in which FW1 of the heavy chain variable region ofthe monoclonal antibodies of the present invention comprises the aminoacid sequence QVQLEESGGGVVRPGRSLRLSCAASGFTFD (SEQ ID NO: 80),QVQLEESGGGVVRPGRSLRLSCAASGFTLD (SEQ ID NO:82),QVQLEESGGGVVRPGRSLRLSCAASGFTFS (SEQ ID NO:81), orQVQLEESGGGVVRPGRSLRLSCAASGFTLS (SEQ ID NO:83); FW2 comprises the aminoacid sequence WIRQAPGKGLEWVT (SEQ ID NO:84) or WIRQAPGKGLEWVG (SEQ IDNO:85); FW3 comprises the amino acid sequenceRFTVSRNNSNNTLSLQMNSLTTEDTAVYYCVR (SEQ ID NO:86) orRLTVSRNNSNNTLSLQMNSLTTEDTAVYYCVR (SEQ ID NO:87). In a particular aspectof each of theses embodiments, FW4 comprises the amino acid sequenceWGQGVLVTVS (SEQ ID NO:88).

The humanized anti-CD22 monoclonal antibodies of the invention thereforeinclude a humanized monoclonal antibody in which the heavy chainvariable region includes FW1 which comprises the amino acid sequenceQVQLEESGGGVVRPGRSLRLSCAASGFTFS (SEQ ID NO:81), FW2 comprises the aminoacid sequence WIRQAPGKGLEWVT (SEQ ID NO:84), FW3 comprises the aminoacid sequence RFTVSRNNSNNTLSLQMNSLTTEDTAVYYCVR (SEQ ID NO:86), and FW4comprises the amino acid sequence WGQGVLVTVS (SEQ ID NO:88).

The humanized anti-CD22 monoclonal antibodies of the present inventionalso include those in which FW1 of the heavy chain variable region ofthe monoclonal antibodies of the present invention comprises the aminoacid sequence ELQLVESGGGFVQPGGSLRLSCAASGFPFR (SEQ ID NO:102),ELQLVESGGGFVQPGGSLRLSCAASGFPLR (SEQ ID NO:103),ELQLVESGGGFVQPGGSLRLSCAASGFPFS (SEQ ID NO:104), orELQLVESGGGFVQPGGSLRLSCAASGFPLS (SEQ ID NO:105); FW2 comprises the aminoacid sequence WVRQGPGKGLVWVS (SEQ ID NO:116); FW3 comprises the aminoacid sequence RVTISRDNAKKMVYPQMNSLRAEDTAMYYCHC (SEQ ID NO:106),RVTISRDNAKKMVYPQMNSLRAEDTAMYYCHR (SEQ ID NO:107),RVTISRDNAKKMVYPQMNSLRAEDTAMYYCHK (SEQ ID NO:108),RVTISRDNAKKMVYPQMNSLRAEDTAMYYCVC (SEQ ID NO:109),RVTISRDNAKKMVYPQMNSLRAEDTAMYYCVR (SEQ ID NO:110),RVTISRDNAKKMVYPQMNSLRAEDTAMYYCVK (SEQ ID NO:111),RVTISRDNAKKMVYPQMNSLRAEDTAMYYCAC (SEQ ID NO:112),RVTISRDNAKKMVYPQMNSLRAEDTAMYYCAR (SEQ ID NO:113), orRVTISRDNAKKMVYPQMNSLRAEDTAMYYCAK (SEQ ID NO:114). In a particular aspectof each of theses embodiments, FW4 comprises the amino acid sequenceWGQGTLVTVS (SEQ ID NO:115).

The humanized anti-CD22 monoclonal antibodies of the invention thereforeinclude a humanized monoclonal antibody in which the heavy chainvariable region includes FW1 which comprises the amino acid sequenceELQLVESGGGFVQPGGSLRLSCAASGFPFS (SEQ ID NO:104), FW2 comprises the aminoacid sequence WVRQGPGKGLVWVS (SEQ ID NO:116), FW3 comprises the aminoacid sequence RVTISRDNAKKMVYPQMNSLRAEDTAMYYCHC (SEQ ID NO:106), and FW4comprises the amino acid sequence WGQGTLVTVS (SEQ ID NO:115).

The present invention also relates to chimeric, human, and humanizedanti-CD22 monoclonal antibodies in which the light chain variable regioncomprises three complementarity determining regions, CDR1, CDR2, andCDR3, and four framework regions, FW1, FW2, FW3, and FW4, in the orderFW1-CDR1-FW2-CDR2-FW3-CDR3-FW4, wherein CDR1 comprises the amino acidsequence KASQSVTNDVA (SEQ ID NO:65), CDR2 comprises the amino acidsequence YASNRYT (SEQ ID NO:66), and CDR3 comprises the amino acidsequence QQDYRSPWT (SEQ ID NO:67). In particular aspects, humanizedanti-CD22 monoclonal antibodies of the invention include a light chainvariable region in which FW1 comprises the amino acid sequenceDIVMTQSPSSLSASVGDRVTITC (SEQ ID NO: 117); those in which FW2 comprisesthe amino acid sequence WYQQKPGKAPKLLIY (SEQ ID NO:118); those in whichFW3 comprises the amino acid sequence GVPSRFSGSGSGTDFTLTISSLQPEDFATYYC(SEQ ID NO:119), GVPDRFSGSGSGTDFTLTISSLQPEDFATYYC (SEQ ID NO:120),GVPSRFSGSGYGTDFTLTISSLQPEDFATYYC (SEQ ID NO:121),GVPSRFSGSGSGTDFTLTISSLQPEDFATYFC (SEQ ID NO:122),GVPDRFSGSGYGTDFTLTISSLQPEDFATYYC (SEQ ID NO:123),GVPDRFSGSGSGTDFTLTISSLQPEDFATYFC (SEQ ID NO:124),GVPSRFSGSGYGTDFTLTISSLQPEDFATYFC (SEQ ID NO:125), orGVPDRFSGSGYGTDFTLTISSLQPEDFATYFC (SEQ ID NO:126); and those in which FW4comprises the amino acid sequence FGGGTKVEIKRT (SEQ ID NO:127).

The present invention further relates to a humanized anti-CD22monoclonal antibody in which the light chain variable region comprisesthree complementarity determining regions, CDR1, CDR2, and CDR3, andfour framework regions, FW1, FW2, FW3, and FW4, in the orderFW1-CDR1-FW2-CDR2-FW3-CDR3-FW4, wherein CDR1 comprises the amino acidsequence KASQSVTNDVA (SEQ ID NO:65), CDR2 comprises the amino acidsequence YASNRYT (SEQ ID NO:66), and CDR3 comprises the amino acidsequence QQDYRSPWT (SEQ ID NO:67), while FW1 comprises the amino acidsequence DIVMTQSPSSLSASVGDRVTITC (SEQ ID NO:117), FW2 comprises theamino acid sequence WYQQKPGKAPKLLIY (SEQ ID NO:118); FW3 comprises theamino acid sequence GVPSRFSGSGSGTDFTLTISSLQPEDFATYYC (SEQ ID NO:119),and FW4 comprises the amino acid sequence FGGGTKVEIKRT (SEQ ID NO:127).

The present invention also relates to a humanized anti-CD22 monoclonalantibody in which the light chain variable region comprises threecomplementarity determining regions, CDR1, CDR2, and CDR3, and fourframework regions, FW1, FW2, FW3, and FW4, in the orderFW1-CDR1-FW2-CDR2-FW3-CDR3-FW4, wherein CDR1 comprises the amino acidsequence KASQSVTNDVA (SEQ ID NO:65), CDR2 comprises the amino acidsequence YASNRYT (SEQ ID NO:66), and CDR3 comprises the amino acidsequence QQDYRSPWT (SEQ ID NO:67), while FW1 comprises the amino acidsequence DIVMTQSPSSLSASVGDRVTITC (SEQ ID NO:117), FW2 comprises theamino acid sequence WYQQKPGKAPKLLIY (SEQ ID NO:118); FW3 comprises theamino acid sequence GVPSRFSGSGSGTDFTLTISSLQPEDFATYFC (SEQ ID NO:122),and FW4 comprises the amino acid sequence FGGGTKVEIKRT (SEQ ID NO:127).

The present invention still further relates to a humanized anti-CD22monoclonal antibody in which the light chain variable region comprisesthree complementarity determining regions, CDR1, CDR2, and CDR3, andfour framework regions, FW1, FW2, FW3, and FW4, in the orderFW1-CDR1-FW2-CDR2-FW3-CDR3-FW4, wherein CDR1 comprises the amino acidsequence KASQSVTNDVA (SEQ ID NO:65), CDR2 comprises the amino acidsequence YASNRYT (SEQ ID NO:66), and CDR3 comprises the amino acidsequence QQDYRSPWT (SEQ ID NO:67), while FW1 comprises the amino acidsequence DIVMTQSPSSLSASVGDRVTITC (SEQ ID NO:117), FW2 comprises theamino acid sequence WYQQKPGKAPKLLIY (SEQ ID NO:118); FW3 comprises theamino acid sequence GVPDRFSGSGYGTDFTLTISSLQPEDFATYFC (SEQ ID NO:126),and FW4 comprises the amino acid sequence FGGGTKVEIKRT (SEQ ID NO:127).

The present invention also relates to humanized anti-CD22 monoclonalantibodies comprising a heavy chain and a light chain, in which theheavy chain variable region includes CDR1, comprising the amino acidsequence DYGVN (SEQ ID NO:62); CDR2, comprising the amino acid sequenceIIWGDGRTDYNSALKS (SEQ ID NO:63); CDR3, comprising the amino acidsequence APGNRAMEY (SEQ ID NO:64), and heavy chain framework regionsFW1-FW4 selected from those disclosed above; and a light chain, in whichthe light chain variable region includes CDR1, comprising the amino acidsequence KASQSVTNDVA (SEQ ID NO:65); CDR2, comprising the amino acidsequence YASNRYT (SEQ ID NO:66); CDR3, comprising the amino acidsequence QQDYRSPWT (SEQ ID NO:67); and light chain framework regionsFW1-FW4 selected from those disclosed above.

The chimeric, human, and humanized anti-CD22 monoclonal antibodies ofthe present invention include those of the IgG1, IgG2, IgG3, or IgG4human isotype.

The present invention further relates to pharmaceutical compositionscomprising the chimeric, human, and humanized anti-CD22 antibodies ofthe invention.

In still another other aspect, the present invention is directed towarda method of treating a B cell malignancy in a human, comprisingadministering to a human in need thereof a therapeutically-effectiveamount of a chimeric, human, or humanized anti-CD22 monoclonal antibodyof the invention.

In a further aspect, the present invention relates to a method oftreating an autoimmune disease or disorder in a human, comprisingadministering to a human in need thereof a therapeutically-effectiveamount of a chimeric, human, or humanized anti-CD22 monoclonal antibodyof the invention.

The present invention further relates to a method of treating orpreventing humoral rejection in a human transplant patient, comprisingadministering to a human in need thereof a therapeutically-effectiveamount of a chimeric, human, or humanized anti-CD22 monoclonal antibodyof the invention.

3.1. DEFINITIONS

As used herein, the terms “antibody” and “antibodies” (immunoglobulins)refer to monoclonal antibodies (including full-length monoclonalantibodies), polyclonal antibodies, multispecific antibodies (e.g.,bispecific antibodies) formed from at least two intact antibodies, humanantibodies, humanized antibodies, camelised antibodies, chimericantibodies, single-chain Fvs (scFv), single-chain antibodies, singledomain antibodies, domain antibodies, Fab fragments, F(ab′)₂ fragments,antibody fragments that exhibit the desired biological activity,disulfide-linked Fvs (sdFv), and anti-idiotypic (anti-Id) antibodies(including, e.g., anti-Id antibodies to antibodies of the invention),intrabodies, and epitope-binding fragments of any of the above. Inparticular, antibodies include immunoglobulin molecules andimmunologically active fragments of immunoglobulin molecules, i.e.,molecules that contain an antigen-binding site. Immunoglobulin moleculescan be of any type (e.g., IgG, IgE, IgM, IgD, IgA and IgY), class (e.g.,IgG1, IgG2, IgG3, IgG4, IgA1 and IgA2) or subclass.

Native antibodies are usually heterotetrameric glycoproteins of about150,000 daltons, composed of two identical light (L) chains and twoidentical heavy (H) chains. Each light chain is linked to a heavy chainby one covalent disulfide bond, while the number of disulfide linkagesvaries between the heavy chains of different immunoglobulin isotypes.Each heavy and light chain also has regularly spaced intrachaindisulfide bridges. Each heavy chain has at one end a variable domain(VH) followed by a number of constant domains. Each light chain has avariable domain at one end (VL) and a constant domain at its other end;the constant domain of the light chain is aligned with the firstconstant domain of the heavy chain, and the light chain variable domainis aligned with the variable domain of the heavy chain. Particular aminoacid residues are believed to form an interface between the light andheavy chain variable domains. Such antibodies may be derived from anymammal, including, but not limited to, humans, monkeys, pigs, horses,rabbits, dogs, cats, mice, etc.

The term “variable” refers to the fact that certain portions of thevariable domains differ extensively in sequence among antibodies and areresponsible for the binding specificity of each particular antibody forits particular antigen. However, the variability is not evenlydistributed through the variable domains of antibodies. It isconcentrated in segments called Complementarity Determining Regions(CDRs) both in the light chain and the heavy chain variable domains. Themore highly conserved portions of the variable domains are called theframework regions (FW). The variable domains of native heavy and lightchains each comprise four FW regions, largely adopting a β-sheetconfiguration, connected by three CDRs, which form loops connecting, andin some cases forming part of, the β-sheet structure. The CDRs in eachchain are held together in close proximity by the FW regions and, withthe CDRs from the other chain, contribute to the formation of theantigen-binding site of antibodies (see, Kabat et al., Sequences ofProteins of Immunological Interest, 5th Ed. Public Health Service,National Institutes of Health, Bethesda, Md. (1991)). The constantdomains are generally not involved directly in antigen binding, but mayinfluence antigen binding affinity and may exhibit various effectorfunctions, such as participation of the antibody in ADCC, CDC, and/orapoptosis.

The term “hypervariable region” when used herein refers to the aminoacid residues of an antibody which are associated with its binding toantigen. The hypervariable regions encompass the amino acid residues ofthe “complementarity determining regions” or “CDRs” (e.g., residues24-34 (L1), 50-56 (L2) and 89-97 (L3) of the light chain variable domainand residues 31-35 (H1), 50-65 (H2) and 95-102 (H3) of the heavy chainvariable domain; Kabat et al., Sequences of Proteins of ImmunologicalInterest, 5th Ed. Public Health Service, National Institutes of Health,Bethesda, Md. (1991)) and/or those residues from a “hypervariable loop”(e.g., residues 26-32 (L1), 50-52 (L2) and 91-96 (L3) in the light chainvariable domain and 26-32 (H1), 53-55 (H2) and 96-101 (H3) in the heavychain variable domain; Chothia and Lesk, J. Mol. Biol., 196:901-917(1987)). “Framework” or “FW” residues are those variable domain residuesflanking the CDRs. FW residues are present in chimeric, humanized,human, domain antibodies, diabodies, vaccibodies, linear antibodies, andbispecific antibodies.

The term “monoclonal antibody” as used herein refers to an antibodyobtained from a population of substantially homogeneous antibodies,i.e., the individual antibodies comprising the population are identicalexcept for possible naturally occurring mutations that may be present inminor amounts. Monoclonal antibodies are highly specific, being directedagainst a single antigenic site. Furthermore, in contrast toconventional (polyclonal) antibody preparations which typically includedifferent antibodies directed against different determinants (epitopes),each monoclonal antibody is directed against a single determinant on theantigen. In addition to their specificity, the monoclonal antibodies areadvantageous in that they are synthesized by hybridoma cells that areuncontaminated by other immunoglobulin producing cells. Alternatively,the monoclonal antibody may be produced by cells stably or transientlytransfected with the heavy and light chain genes encoding the monoclonalantibody.

The modifier “monoclonal” indicates the character of the antibody asbeing obtained from a substantially homogeneous population ofantibodies, and is not to be construed as requiring engineering of theantibody by any particular method. The term “monoclonal” is used hereinto refer to an antibody that is derived from a clonal population ofcells, including any eukaryotic, prokaryotic, or phage clone, and notthe method by which the antibody was engineered. For example, themonoclonal antibodies to be used in accordance with the presentinvention may be made by the hybridoma method first described by Kohleret al., Nature, 256:495 (1975), or may be made by any recombinant DNAmethod (see, e.g., U.S. Pat. No. 4,816,567), including isolation fromphage antibody libraries using the techniques described in Clackson etal., Nature, 352:624-628 (1991) and Marks et al., J. Mol. Biol.,222:581-597 (1991), for example. These methods can be used to producemonoclonal mammalian, chimeric, humanized, human, domain antibodies,diabodies, vaccibodies, linear antibodies, and bispecific antibodies.

The term “chimeric” antibodies includes antibodies in which at least oneportion of the heavy and/or light chain is identical with or homologousto corresponding sequences in antibodies derived from a particularspecies or belonging to a particular antibody class or subclass, and atleast one other portion of the chain(s) is identical with or homologousto corresponding sequences in antibodies derived from another species orbelonging to another antibody class or subclass, as well as fragments ofsuch antibodies, so long as they exhibit the +desired biologicalactivity (U.S. Pat. No. 4,816,567; Morrison et al., Proc. Natl. Acad.Sci. USA, 81:6851-6855 (1984)). Chimeric antibodies of interest hereininclude “primatized” antibodies comprising variable domainantigen-binding sequences derived from a nonhuman primate (e.g., OldWorld Monkey, such as baboon, rhesus or cynomolgus monkey) and humanconstant region sequences (U.S. Pat. No. 5,693,780).

“Humanized” forms of nonhuman (e.g., murine) antibodies are chimericantibodies that contain minimal sequence derived from nonhumanimmunoglobulin. For the most part, humanized antibodies are humanimmunoglobulins (recipient antibody) in which the native CDR residuesare replaced by residues from the corresponding CDR of a nonhumanspecies (donor antibody) such as mouse, rat, rabbit or nonhuman primatehaving the desired specificity, affinity, and capacity. In someinstances, one or more FW region residues of the human immunoglobulinare replaced by corresponding nonhuman residues. Furthermore, humanizedantibodies may comprise residues that are not found in the recipientantibody or in the donor antibody. These modifications are made tofurther refine antibody performance. In general, a humanized antibodyheavy or light chain will comprise substantially all of at least one ormore variable domains, in which all or substantially all of the CDRscorrespond to those of a nonhuman immunoglobulin and all orsubstantially all of the FWs are those of a human immunoglobulinsequence. In certain embodiments, the humanized antibody will compriseat least a portion of an immunoglobulin constant region (Fc), typicallythat of a human immunoglobulin. For further details, see, Jones et al.,Nature, 321:522-525 (1986); Riechmann et al., Nature, 332:323-329(1988); and Presta, Curr. Op. Struct. Biol., 2:593-596 (1992).

A “human antibody” can be an antibody derived from a human or anantibody obtained from a transgenic organism that has been “engineered”to produce specific human antibodies in response to antigenic challengeand can be produced by any method known in the art. In certaintechniques, elements of the human heavy and light chain loci areintroduced into strains of the organism derived from embryonic stem celllines that contain targeted disruptions of the endogenous heavy chainand light chain loci. The transgenic organism can synthesize humanantibodies specific for human antigens, and the organism can be used toproduce human antibody-secreting hybridomas. A human antibody can alsobe an antibody wherein the heavy and light chains are encoded by anucleotide sequence derived from one or more sources of human DNA. Afully human antibody also can be constructed by genetic or chromosomaltransfection methods, as well as phage display technology, or in vitroactivated B cells, all of which are known in the art.

“Antibody-dependent cell-mediated cytotoxicity” and “ADCC” refer to acell-mediated reaction in which non-specific cytotoxic cells (e.g.,Natural Killer (NK) cells, neutrophils, and macrophages) recognize boundantibody on a target cell and subsequently cause lysis of the targetcell. In one embodiment, such cells are human cells. While not wishingto be limited to any particular mechanism of action, these cytotoxiccells that mediate ADCC generally express Fc receptors (FcRs). Theprimary cells for mediating ADCC, NK cells, express FcγRIII, whereasmonocytes express FcγRI, FcγRII, FcγRIII and/or FcγRIV. FcR expressionon hematopoietic cells is summarized in Ravetch and Kinet, Annu. Rev.Immunol., 9:457-92 (1991). To assess ADCC activity of a molecule, an invitro ADCC assay, such as that described in U.S. Pat. No. 5,500,362 or5,821,337 may be performed. Useful effector cells for such assaysinclude peripheral blood mononuclear cells (PBMC) and Natural Killer(NK) cells. Alternatively, or additionally, ADCC activity of themolecules of interest may be assessed in vivo, e.g., in an animal modelsuch as that disclosed in Clynes et al., Proc. Natl. Acad. Sci. (USA),95:652-656 (1998).

“Complement dependent cytotoxicity” or “CDC” refers to the ability of amolecule to initiate complement activation and lyse a target in thepresence of complement. The complement activation pathway is initiatedby the binding of the first component of the complement system (C1q) toa molecule (e.g., an antibody) complexed with a cognate antigen. Toassess complement activation, a CDC assay, e.g., as described inGazzano-Santaro et al., J. Immunol. Methods, 202:163 (1996), may beperformed.

“Effector cells” are leukocytes which express one or more FcRs andperform effector functions. Preferably, the cells express at leastFcγRI, FCγRII, FcγRIII and/or FcγRIV and carry out ADCC effectorfunction. Examples of human leukocytes which mediate ADCC includeperipheral blood mononuclear cells (PBMC), natural killer (NK) cells,monocytes, cytotoxic T cells and neutrophils. In certain embodiments ofthe invention, PBMCs and NK cells are used. In one embodiment, theeffector cells are human cells.

The terms “Fc receptor” or “FcR” are used to describe a receptor thatbinds to the Fc region of an antibody. In one embodiment, the FcR is anative sequence human FcR. Moreover, in certain embodiments, the FcR isone which binds an IgG antibody (a gamma receptor) and includesreceptors of the FcγRI, FcγRII, FcγRIII, and FcγRIV subclasses,including allelic variants and alternatively spliced forms of thesereceptors. FcγRII receptors include FcγRIIA (an “activating receptor”)and FcγRIIB (an “inhibiting receptor”), which have similar amino acidsequences that differ primarily in the cytoplasmic domains thereof.Activating receptor FcγRIIA contains an immunoreceptor tyrosine-basedactivation motif (ITAM) in its cytoplasmic domain. Inhibiting receptorFcγRIIB contains an immunoreceptor tyrosine-based inhibition motif(ITIM) in its cytoplasmic domain. (See, Daëron, Annu. Rev. Immunol.,15:203-234 (1997)). FcRs are reviewed in Ravetech and Kinet, Annu. Rev.Immunol., 9:457-92 (1991); Capel et al., Immunomethods, 4:25-34 (1994);and de Haas et al., J. Lab. Clin. Med., 126:330-41 (1995). Other FcRs,including those to be identified in the future, are encompassed by theterm “FcR” herein. The term also includes the neonatal receptor, FcRn,which is responsible for the transfer of maternal IgGs to the fetus(Guyer et al., Immunol., 117:587 (1976) and Kim et al., J. Immunol.,24:249 (1994)).

“Fv” is the minimum antibody fragment which contains a completeantigen-recognition and binding site. This region consists of a dimer ofone heavy and one light chain variable domain in tight, non-covalent orcovalent association. It is in this configuration that the three CDRs ofeach variable domain interact to define an antigen-binding site on thesurface of the V_(H)-V_(L) dimer. Collectively, the six CDRs conferantigen-binding specificity to the antibody. However, even a singlevariable domain (or half of an Fv comprising only three CDRs specificfor an antigen) has the ability to recognize and bind antigen, althoughat a lower affinity than the entire binding site.

“Affinity” of an antibody for an epitope to be used in the treatment(s)described herein is a term well understood in the art and means theextent, or strength, of binding of antibody to epitope. Affinity may bemeasured and/or expressed in a number of ways known in the art,including, but not limited to, equilibrium dissociation constant (KD orKd), apparent equilibrium dissociation constant (KD′ or Kd′), and IC50(amount needed to effect 50% inhibition in a competition assay). It isunderstood that, for purposes of this invention, an affinity is anaverage affinity for a given population of antibodies which bind to anepitope. Values of KD′ reported herein in terms of mg IgG per mL ormg/mL indicate mg Ig per mL of serum, although plasma can be used. Whenantibody affinity is used as a basis for administration of the treatmentmethods described herein, or selection for the treatment methodsdescribed herein, antibody affinity can be measured before and/or duringtreatment, and the values obtained can be used by a clinician inassessing whether a human patient is an appropriate candidate fortreatment.

An “epitope” is a term well understood in the art and means any chemicalmoiety that exhibits specific binding to an antibody. An “antigen” is amoiety or molecule that contains an epitope, and, as such, alsospecifically binds to antibody.

A “B cell surface marker” as used herein is an antigen expressed on thesurface of a B cell which can be targeted with an agent which bindsthereto. Exemplary B cell surface markers include the CD10, CD22, CD20,CD21, CD22, CD23, CD24, CD25, CD37, CD53, CD72, CD73, CD74, CD75, CD77,CD79a, CD79b, CD80, CD81, CD82, CD83, CD84, CD85, and CD86 leukocytesurface markers. The B cell surface marker of particular interest ispreferentially expressed on B cells compared to other non-B cell tissuesof a mammal and may be expressed on both precursor B cells and matureB-lineage cells. In one embodiment, the marker is CD22, which is foundon B cells at various stages of differentiation.

The term “antibody half-life” as used herein means a pharmacokineticproperty of an antibody that is a measure of the mean survival time ofantibody molecules following their administration. Antibody half-lifecan be expressed as the time required to eliminate 50 percent of a knownquantity of immunoglobulin from the patient's body or a specificcompartment thereof, for example, as measured in serum or plasma, i.e.,circulating half-life, or in other tissues. Half-life may vary from oneimmunoglobulin or class of immunoglobulin to another. In general, anincrease in antibody half-life results in an increase in mean residencetime (MRT) in circulation for the antibody administered.

The term “isotype” refers to the classification of an antibody's heavyor light chain constant region. The constant domains of antibodies arenot involved in binding to antigen, but exhibit various effectorfunctions. Depending on the amino acid sequence of the heavy chainconstant region, a given human antibody or immunoglobulin can beassigned to one of five major classes of immunoglobulins: IgA, IgD, IgE,IgG, and IgM. Several of these classes may be further divided intosubclasses (isotypes), e.g., IgG1 (gamma 1), IgG2 (gamma 2), IgG3 (gamma3), and IgG4 (gamma 4), and IgA1 and IgA2. The heavy chain constantregions that correspond to the different classes of immunoglobulins arecalled α, δ, ε, γ, and μ, respectively. The structures andthree-dimensional configurations of different classes of immunoglobulinsare well-known. Of the various human immunoglobulin classes, only humanIgG1, IgG2, IgG3, IgG4, and IgM are known to activate complement. HumanIgG1 and IgG3 are known to mediate ADCC in humans. Human light chainconstant regions may be classified into two major classes, kappa andlambda

As used herein, the term “immunogenicity” means that a compound iscapable of provoking an immune response (stimulating production ofspecific antibodies and/or proliferation of specific T cells).

As used herein, the term “antigenicity” means that a compound isrecognized by an antibody or may bind to an antibody and induce animmune response.

As used herein, the term “avidity” is a measure of the overall bindingstrength (i.e., both antibody arms) with which an antibody binds anantigen. Antibody avidity can be determined by measuring thedissociation of the antigen-antibody bond in antigen excess using anymeans known in the art, such as, but not limited to, by the modificationof indirect fluorescent antibody as described by Gray et al., J. Virol.Meth., 44:11-24. (1993).

By the terms “treat,” “treating” or “treatment of” (or grammaticallyequivalent terms) it is meant that the severity of the subject'scondition is reduced or at least partially improved or amelioratedand/or that some alleviation, mitigation or decrease in at least oneclinical symptom is achieved and/or there is an inhibition or delay inthe progression of the condition and/or prevention or delay of the onsetof a disease or illness. Thus, the terms “treat,” “treating” or“treatment of” (or grammatically equivalent terms) refer to bothprophylactic and therapeutic treatment regimes.

As used herein, a “sufficient amount” or “an amount sufficient to”achieve a particular result refers to an amount of an antibody orcomposition of the invention that is effective to produce a desiredeffect, which is optionally a therapeutic effect (i.e., byadministration of a therapeutically effective amount). For example, a“sufficient amount” or “an amount sufficient to” can be an amount thatis effective to deplete B cells.

A “therapeutically effective” amount as used herein is an amount thatprovides some improvement or benefit to the subject. Alternativelystated, a “therapeutically effective” amount is an amount that providessome alleviation, mitigation, and/or decrease in at least one clinicalsymptom. Clinical symptoms associated with the disorders that can betreated by the methods of the invention are well-known to those skilledin the art. Further, those skilled in the art will appreciate that thetherapeutic effects need not be complete or curative, as long as somebenefit is provided to the subject.

4. BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A-B: (A) Nucleotide [SEQ ID NO:1] and amino acid [SEQ ID NO:2] ofthe chimeric HB22.7 variable heavy (VH) chain. The Kozak sequence,leader sequence, and 5′ fragment of the human gamma 1 constant region upto the natural ApaI restriction site are indicated. The vector encodingthis sequence is designated HB22.7Hc.pG1D20. (B) Nucleotide and aminoacid sequences of chHB227 and the HB227 variable heavy chain (VH) region[SEQ ID NO:5 and SEQ ID NO:7]. CDRs are underlined. Leader sequences areitalicized. The Kabat numbering system is used to identify specificresidues.

FIG. 2A-B: (B) Nucleotide [SEQ ID NO: 3] and amino acid [SEQ ID NO:4]sequence of the chimeric HB22.7 variable light (VK) chain. The Kozaksequence, leader sequence, and 5′ splice donor site are indicated. Thevector encoding this sequence is designated HB22.7Kc.pKN10. (B)Nucleotide and amino acid sequences of chHB227 and HB227 variable lightchain region (VL) [SEQ ID NO:26 and SEQ ID NO:27]. CDRs are underlined.Leader sequences are italicized. The Kabat numbering system is used toidentify specific residues.

FIG. 3: Binding of the chimeric HB22.7 antibody (chHB227) toCD22-expressing BHK cells. The parental mouse HB22.7 antibody (closedcircles) was used as a reference standard. The binding profile of thechHB227 (closed squares) closely matches that of the mouse parentalcontrol. As a negative control, the binding of each antibody to BHKcells not expressing CD22 is also shown, mouse HB22.7 (open circles),chHB227 (open squares).

FIG. 4: Amino acid sequence of parental mouse HB22.7 VH [SEQ ID NO:7]and high homology acceptor VH (VH46898) [SEQ ID NO:6]. Canonical (c),Vernier (v), Interface (i), and residues within the 200% Van der Waal'sradius (*) of are shown in the context of the Kabat numbering system.

FIG. 5A-G: Generation of humanized variants of mouse VH, HB22.7 [SEQ IDNO: 5 and 7]. (A and B) Generation of HB227-(V2-70+IC4) heavy chainvariant. Germline human FW1, FW2 and FW3 from human V2-70 VH [SEQ IDNO:8 and 9], and FW4 from human IC4 [SEQ ID NO: 10 and 11] were used asacceptor sequences for the parental mouse HB22.7 VH CDR1, CDR2, and CDR3sequences. The resulting humanized VH construct was termedHB227-(V2-70+IC4) [SEQ ID NO: 12 and 13]. CDR sequences are underlined.(C and D) Generation of HB227-VH46898 [SEQ ID NO: 14 and 15] andHB227RHB [SEQ ID NO: 16 and 17] high homology variants. Singlenucleotide substitutions were introduced in the HB227-(V2-70+IC4) FWsequence so as to recreate the HB227-VH46898 FW coding sequence [SEQ IDNO: 14 and 15]. The addition of the V2-50 leader sequence resulted inthe HB227RHB humanized construct [SEQ ID NO: 16 and 17]. CDR sequencesare underlined. Leader sequences are italicized. (E-G) Generation ofRHC, RHD, RHE, and RHF variants of HB227RHB. In an effort to increasebinding activity of HB227RHB, the mismatched Vernier residues at Kabatpositions 73 and 49 were backmutated to the corresponding mouse residuesindividually or simultaneously to generate HB227RHE [SEQ ID NO:22 and23], HB227RHD [SEQ ID NO:20 and 21], and HB227RHC [SEQ ID NO:18 and 19]respectively. The HB227RHF construct [SEQ ID NO:24 and 25] was derivedfrom HB227RHC by backmutation of a mismatched mouse canonical residue atKabat position 24. CDR sequences are underlined. Leader sequences areitalicized.

FIG. 6: Alignment of human light chain framework acceptor genes withHB22.7 variable light chain (VL) sequence. Among the human variablekappa light chains (VK) with homology to the parental mouse HB22.7 VK[SEQ ID NO:26 and 27], the VL Clone 47 human sequence was chosen as theacceptor for the mouse HB22.7 VK CDRs. Because Clone 47 DNA sequenceinformation was not available, a closely related human VK gene, AJ388641[SEQ ID NO: 28 and 29], was mutated by replacing single nucleotides soas to recreate the Clone 47 FW regions. The resulting construct wasreferred to as AJ388641+Clone 47 FW [SEQ ID NO: 30 and 31]. Canonical(c), Vernier (v), Interface (i), and residues are shown in the contextof the Kabat numbering system. CDR sequences are underlined.

FIG. 7A-D: Generation of humanized VK light chain from parental mouseHB22.7 VK sequence. (A and B) The humanized version of the HB22.7 VKgene was generated by PCR cloning of the HB22.7 VK CDRs into the humanClone 47 FW regions. The Clone 47 FW regions were generated by mutatinga closely related human VK gene (AJ3888641 [SEQ ID NO: 28 and 29] CDRsequences are underlined. (C and D) Addition of DPK018 leader sequenceto HB227-Clone 47 resulting in the HB227-RKA humanized VK chain [SEQ IDNO: 34 and 35]. HB227-RKB variant [SEQ ID NO: 36 and 37] of HB227-RKAwas generated by backmutation (human to mouse) of a single interfaceresidue at Kabat position 87 (Y87F). HB227-RKC [SEQ ID NO: 38 and 39]was generated by backmutating two additional residues, S60D and S67Ywhich were potential binding residues. CDR sequences are underlined.Leader sequences are italicized.

FIG. 8: CD22-binding of antibodies comprising HB227RHB, RHC, or chimericHB22.7 heavy chain (chH) with chimeric HB22.7 light chain (chL) orHB227RKA light chain.

FIG. 9: CD22-binding of antibodies comprising chHB227 (chH+chL) andHB227RHF heavy chain associated with chL, HB227RKA, HB227RKB, orHB227RKC light chains.

FIG. 10: chHB227 antibody and the humanized HB227RHF+HB227RKC antibodyeach compete similarly with the parental mouse antibody HB22.7 forbinding to CD22. The figure shows the percentage binding to CD22 by thechHB227 antibody or the humanized (RHF+RKC) antibody in the presence ofincreasing concentrations of the parental mouse HB22.7 antibody. Fiftypercent inhibition (IC₅₀) is achieved at about 4 μg/ml of the chimericantibody (grey rectangle).

FIG. 11: CD22 binding of antibodies comprising HB227RKC or the chL,paired with either the chH or one of the humanized HB227 heavy chains,RHB, RHC, RHF, or RHO.

FIG. 12: Identification of human VH acceptor sequence. The Canonical(c), Vernier (v), and Interface (i) residues within HB227 VH [SEQ ID NO:5 and 7] are denoted in the context of the Kabat numbering system. Thoseresidues within the 200% Van der Waal's radius envelope (*) are alsodepicted. Three canonical residues, V24, G26, F27; one Vernier, N73; andthe VL interaction residues V37, Q39, L45, and Y91 lie outside the 200%VdW envelope and thus were not targeted for backmutation to the parentalresidue. Human VH gene databases were searched for VH sequences thatconserved these residues but had low framework homology with HB22.7.Five such sequences were identified with AJ556657 sequence [SEQ ID NO:40 and 41] being selected as the low identity acceptor VH for the HB227VH CDRs. CDR sequences are underlined.

FIG. 13A-G: Generation of humanized, FW variants of HB22.7 VH. (A-B)Generation of HB227-AJ556657. The HB227-AJ556657 VH [SEQ ID NO: 42 and43] was accomplished by inserting the HB22.7 CDRs into the FW regions ofAJ556657 [SEQ ID NO: 40 and 41]. (C-D) Generation of HB227RHO andHB227RHOv2. The HB227RHO [SEQ ID NO: 46 and 47] and H227RHOv2 [SEQ IDNO: 48 and 49] were generated by sequential backmutation of fourresidues within the 200% VdW radius (F29L, D30S, T49G, and F67L) andreplacement of the VH3-30 leader sequence [SEQ ID NO: 44 and 45] withthe VH2-50 leader sequence. (E-G) HB227RHOv2 variants were generated byselectively reversing one or more of the backmutations at Kabatpositions 29, 30, 49, and 67. The resulting variants, HB227RHOv2A [SEQID NO: 50 and 51], HB227RHOv2B [SEQ ID NO: 52 and 53], HB227RHOv2C [SEQID NO: 54 and 55], HB227RHOv2D [SEQ ID NO: 56 and 57], HB227RHOv2ACD[SEQ ID NO: 58 and 59], and HB227RHOv2ABCD [SEQ ID NO: 60 and 61 ] weresubsequently screened for hCD22 binding activity. CDR sequences areunderlined. Leader sequences are italicized.

FIG. 14A-E: CD22 binding by RHOv2A, -B, -C and D, each expressed withthe humanized RKC light chain. In each panel, the binding of CD22 by thechH+chL antibody is shown for comparison (filled squares) (A) RHOv2. (B)RHOv2A. (C) RHOv2B. (D) RHOv2C. (E) RHOv2D. The A-D designations referto the removal of one of the four back mutations, F29L (A), D30S (B),T49G (C), and F67L (D) from the RHOv2 sequence. RHOv2 contains all fourmutations. In each of RHOv2A-D, the single back mutation indicated bythe letter A, B, C, or D, has been removed, leaving the other three backmutations intact.

FIG. 15A-E: CD22 binding by RHOv2ACD and RHOv2ABCD. In each panel, thebinding of CD22 by the chH+chL antibody is shown for comparison (filledcircles). (A) CD22 binding by the humanized antibody comprising theheavy chain sequence, RHF, and the light chain sequence, RKC, (opencircles) is comparable to that of the fully chimeric antibody (filledcircles). CD22 binding by RHOv2ACD (B) and RHOv2ABCD (C), each pairedwith the humanized light chain, RKA. CD22 binding by RHOv2ACD (D) andRHOv2ABCD (E), each paired with the humanized light chain, RKC. The A-Ddesignations refer to the removal of one of the four back mutations,F29L (A), D30S (B), T49G (C), and F67L (D). RHOv2ACD contains only theD30S back mutation; RHOv2ABCD contains no back mutations.

FIGS. 16A-C: provides a compilation of human VH amino acid sequences(SEQ ID NOs:130-198) with overall low FW sequence identity relative toHB22.7 VH but which comprise conserved residues at positions 24, 26, 39,45, and 73.

FIG. 17: depicts the amino acid sequence of five potential, overall lowsequence identity VH acceptor sequences (SEQ ID NOs:7, 41, 199-202)selected from among those depicted in FIG. 16. In particular, the VHacceptor sequences of HB22.7 (SEQ ID NO:7), AJ556657 (SEQ ID NO:41),AB067248 (SEQ ID NO:199), AJ556642 (SEQ ID NO:200), AJ556644 (SEQ IDNO:201), and AF376954 (SEQ ID NO:202) are shown with the correspondinghumanized version names.

FIG. 18: provides binding affinity of murine antibody HB22.7 andhumanized antibody RHOv2ACD/RKA to CD22-transfected CHO cells.

FIG. 19: provides binding affinity of Alexa-fluor labeled murine HB22.7and humanized RHOv2ACD/RKA antibodies by FACS on Daudi cells.

FIGS. 20A and B: provides cell surface binding and CD22 internalizationof murine HB22.7 and humanized RHOv2ACD/RKA antibodies on Daudi lymphomaB cells. (A) provides the kinetics of binding activity and (B) providesinternalization of each antibody on the Daudi lymphoma B cells.

FIGS. 21A and B: provides cell surface binding and CD22 internalizationof murine HB22.7 and humanized RHOv2ACD/RKA antibodies on humantonsillar B cells. (A) provides the kinetics of binding activity and (B)provides internalization of each antibody on human tonsillar B cells.

FIGS. 22A and B: provides cell surface binding and CD22 internalizationof murine HB22.7 and humanized RHOv2ACD/RKA antibodies on humanperipheral blood B cells. (A) provides the kinetics of binding activityand (B) provides internalization of each antibody on human peripheralblood B cells.

FIG. 23: compares CD22 internalization by blocking (HB22.7 andRHOv2ACD/RKA) and non-blocking (HB22.15) anti-hCD22 antibodies usingDaudi lymphoma cell lines.

FIG. 24: provides ADCC effector function of humanized anti-hCD22antibody RHOv2ACD/RKA on Raji lymphoma cells.

FIGS. 25A and B: provides CDC effector function of humanized anti-hCD22antibody RHOv2ACD/RKA on Raji lymphoma cells. (A) shows effect ofRituxan; and (B) shows effect of RHOv2ACD/RKA on CDC on Raji cells.

FIG. 26A-D: shows that each of HB22.7 and RHOv2ACD/RKA block binding ofDaudi cells to hCD22-expressing COS cells. (A) co-culture of COS andDaudi cells; (B) co-culture of COS cells expressing hCD22 and Daudicells; (C) co-culture of COS cells expressing hCD22 and Daudi cells, theCOS cells expressing hCD22 were pre-incubated with HB22.7; (D)co-culture of COS cells expressing hCD22 and Daudi cells, the COS cellsexpressing hCD22 were pre-incubated with RHOv2ACD/RKA.

FIGS. 27A and B: provides effect of humanized anti-hCD22 antibodyRHOv2ACD/RKA on CD22 signaling activity, Ca-flux, in Ramos B cells. (A)provides a Ca-flux dose response of Ramos B cells to B cell receptorcrosslinking; (B) provides Ca-flux response of Ramos B cells to hCD22antibody RHOv2ACD/RKA.

FIGS. 28A and B: shows that anti-IgM-induced Ca-flux in human peripheralB cells is enhanced by ligand blocking anti-hCD22 antibodies, HB22.7 andRHOv2ACD/RKA, but not non-ligand blocking anti-hCD22 antibody, HB22.15.(A) provides Ca-flux in human peripheral B cells contacted with anti-μ,RHOv2ACD/RKA+anti-μ, and isotype control antibody R347+ anti-μantibodies; (B) provides Ca-flux in human peripheral B cells bound byanti-μ, HB22.7+ anti-μ, and HB22.15 (a non-ligand binding hCD22antibody)+anti-μ antibodies.

FIG. 29A-H: provides the effect of anti-IgM with or without anti-CD22antibodies, HB22.7 and RHOv2ACD/RKA, on Ramos B cell survival. Treatmentof Ramos B cells was as follows: (A) no antibody; (B) 10 μg/ml HB22.7;(C) 10 μg/ml RHOv2ACD/RKA; (D) 3.3 μg/ml anti-IgM; (E) 3.3 μg/mlanti-IgM+10 μg/ml HB22.7; (F) 3.3 μg/ml anti-IgM+10 μg/ml RHOv2ACD/RKA;(G) 10 μg/ml anti-IgM; (H) 10 μg/ml anti-IgM+10 μg/ml HB22.7. Analysiswas performed by forward and side scatter.

FIG. 30: provides dissociation of murine antibody HB22.7 and humanizedRHOv2ACD/RKA antibody from Daudi cells.

5. DETAILED DESCRIPTION OF THE INVENTION

The present invention relates to human, humanized, or chimeric anti-CD22antibodies that bind to the human CD22 antigen, as well as tocompositions comprising those antibodies. In certain embodiments thehuman, humanized, or chimeric anti-CD22 antibodies of the invention arethose that mediate antigen-dependent-cell-mediated-cytotoxicity (ADCC).In particular embodiments, the present invention is directed towardcompositions comprising human, humanized, or chimeric anti-CD22antibodies of the invention are of the IgG1 and/or IgG3 human isotype,as well as to human, humanized, or chimeric anti-CD22 antibodies of theIgG2 and/or IgG4 human isotype, that preferably mediate human ADCC, CDC,and/or apoptosis.

The present invention provides chimeric and humanized versions ofanti-CD22 mouse monoclonal antibody, HB22.7. In one embodiment, thehumanized anti-CD22 antibodies bind to human CD22 with an affinitycomparable to that of the mouse monoclonal antibody designated HB22.7 orcomparable to that of the chHB227 antibody. The anti-CD22 antibodies ofthe invention comprise four human or humanized framework regions of theimmunoglobulin heavy chain variable region (“VH”) and four human orhumanized framework regions of the immunoglobulin light chain variableregion (“VK”). The invention further comprises heavy and/or light chainFW regions that contain one or more backmutations in which a human FWresidue is exchanged for the corresponding residue present in theparental mouse heavy or light chain. The invention comprises anti-CD22antibodies having one or more CDRs present in the heavy and light chainsof the antibody produced by the parental mouse hybridoma HB22.7. anddeposited with the American Type Culture Collection (“ATCC”) underaccession no. ATCC Designation: HB11347. The amino acid sequences forCDR1, CDR2, and CDR3 of the heavy chain are identified as SEQ ID NO:62,SEQ ID NO:63, and SEQ ID NO: 64 respectively. The amino acid sequencesfor CDR1, CDR2 and CDR3 of the light chain are identified as SEQ IDNO:65, SEQ ID NO:66, and SEQ ID NO:67 respectively.

In other embodiments, the human or humanized VH framework regions ofantibodies of the invention comprise one or more of the followingresidues: a valine (V) at position 24 of framework region 1, a glycine(G) at position 49 of framework region 2, and an asparagine (N) atposition 73 of framework region 3, numbered according to Kabat. Kabatnumbering is based on the seminal work of Kabat et al. (1991) Sequencesof Proteins of Immunological Interest, Publication No. 91-3242,published as a three volume set by the National Institutes of Health,National Technical Information Service (hereinafter “Kabat”). Kabatprovides multiple sequence alignments of immunoglobulin chains fromnumerous species antibody isotypes. The aligned sequences are numberedaccording to a single numbering system, the Kabat numbering system. TheKabat sequences have been updated since the 1991 publication and areavailable as an electronic sequence database (latest downloadableversion 1997). Any immunoglobulin sequence can be numbered according toKabat by performing an alignment with the Kabat reference sequence.Accordingly, the Kabat numbering system provides a uniform system fornumbering immunoglobulin chains. Unless indicated otherwise, allimmunoglobulin amino acid sequences described herein are numberedaccording to the Kabat numbering system. Similarly, all single aminoacid positions referred to herein are numbered according to the Kabatnumbering system.

Exemplary VH and VK antibody regions of the invention were depositedwith the American Type Culture Collection (ATCC). In particular, aplasmid encoding the humanized anti-CD22 VH sequence of the inventiondesignated RHOv2 (SEQ ID NO:48 and SEQ ID NO:49), was deposited underATCC deposit no. PTA-7372, on Feb. 9, 2006. A plasmid encoding thehumanized anti-CD22 VH sequence of the invention designated RHOv2ACD(SEQ ID NO:58 and SEQ ID NO:59), was deposited under ATCC deposit no.PTA-7373, on Feb. 9, 2006. A plasmid encoding the humanized anti-CD22 VKsequence of the invention, RKA (SEQ ID NO:34 and SEQ ID NO:35), wasdeposited under ATCC deposit no. PTA-7370, on Feb. 9, 2006. A plasmidencoding the humanized anti-CD22 VK sequence of the invention, RKC (SEQID NO:38 and SEQ ID NO:39), was deposited under ATCC deposit no.PTA-7371, on Feb. 9, 2006.

In one embodiment of the invention, the human or humanized VH frameworkregions of antibodies of the invention have an amino acid sequenceidentity with the HB22.7 antibody VH within the range of from about 64%to about 100%. In certain aspects of this embodiment, the human orhumanized VH framework regions of antibodies of the invention have anamino acid sequence identity with the HB22.7 antibody VH that is atleast 64%, at least 65%, at least 70%, at least 75%, at least 80%, atleast 85%, at least 90%, or at least 95%.

In particular embodiments, the human or humanized VH framework regionsof antibodies of the invention have an amino acid sequence identity withthe HB22.7 antibody VH of at least 56 out of 87 amino acids (56/87) Inparticular embodiments, the VH framework amino acid sequence identity isat least 56/87, 57/87, 58/87, 59/87, 60/87, 61/87, 62/87, 63/87, 64/87,65/87, 66/87, 67/87, 68/87, 69/87, 70/87, 71, 87, 72/87, 73/87m 74/87,75/87, 76/87, 77.87, 78/87, 79/87, 80/87, 81/87, 82/87, 83/87, 84/87,85/87, 86/87, or 87/87 amino acids. Preferably, the VH sequences havehigh sequence identity among the Vernier amino acid residues of HB22.7(see FIG. 4), for example a Vernier sequence identity of at least 10 outof 16 (10/16), at least 11/16, at least 12/16, at least 13/16, at least14/16, or at least 15/16 Vernier residues. In another embodiment, themismatch of a Vernier amino acid residue is a conservative amino acidsubstitution. A mismatch that is a conservative amino acid substitutionis one in which the mismatched amino acid has physical and chemicalproperties similar to the Vernier amino acid, e.g., the mismatchedresidue has similar characteristics of polarity (polar or nonpolar),acidity (acidic or basic), side chain structure (e.g., branched orstraight, or comprising a phenyl ring, a hydroxyl moiety, or a sulfurmoiety) to the Vernier residue.

In other embodiments, the mismatch of a Vernier amino acid residue is anon-conservative amino acid substitution. A mismatch that is anon-conservative amino acid substitution is one in which the mismatchedamino acid does not have physical and chemical properties similar to theVernier amino acid, e.g., the mismatched residue may have a differentpolarity, acidity, or side chain structure (e.g., branched or straight,or comprising a phenyl ring, a hydroxyl moiety, or a sulfur moiety) ascompared to the Vernier residue to be replaced.

In further particular embodiments, the human or humanized VH frameworkregions of antibodies of the invention have framework regions selectedfor identity or conservative mismatches at one or more of the followingVernier, Interface or Canonical residue positions: 24, 26, 27, 37, 39,45, 73, and 91, all of which are located outside the 200% van der Waal's(“VdW”) envelope described by Winter in U.S. Pat. No. 6,548,640. One ormore of the mismatched Vernier, Interface and Canonical residues withinthe 200% van der Waal's (“VdW”) envelope as described by Winter in U.S.Pat. No. 6,548,640 are changed, e.g., by mutagenesis, to match thecorresponding Vernier or canonical amino acid residue of the HB22.7framework region.

In other embodiments, the human or humanized VK framework regionscomprise one or more of the following residues: an aspartate (D) atposition 60 of framework region 3, a tyrosine (Y) at position 67 offramework region 3, and a phenylalanine (F) at position 87 of frameworkregion 3.

In particular embodiments, a humanized VH is expressed with a humanizedVK to produce a humanized anti-CD22 antibody. In another embodiment, ahumanized anti-CD22 antibody of the invention comprises a VH sequenceselected from the group comprising the sequence designated HB22.7RHF(SEQ ID NO:24 and 25), HB227RHO (SEQ ID NO:46 and 47), HB227RHOv2, (SEQID NO:48 and 49), HB227RHOv2A, (SEQ ID NO:50 and 51), HB227RHOv2B, (SEQID NO:52 and 53), HB227RHOv2C, (SEQ ID NO:54 and 55), HB227RHOv2D, (SEQID NO:56 and 57), HB227RHOv2ACD (SEQ ID NO:58-59) and HB227RHOv2ABCD,(SEQ ID NO:60 and 61). Any of the aforementioned VH sequences may bepaired with the VK sequence designated HB227RKA (SEQ ID NO:34 and 35)HB227RKB (SEQ ID NO:36 and 37, or HB227RKC (SEQ ID NO:38 and 39) (“RKA”,“RKB”, or “RKC”). In a particular embodiment, the humanized anti-CD22antibody comprises the VH sequence RHF and the VK sequence RKC, the VHsequence RHO and the VK sequence RKC, the VH sequence RHOv2 and the VKsequence RKC, or the VH sequence RHOv2ACD and the VK sequence RKC.

In other embodiments, the humanized anti-CD22 antibody comprises the VHsequence RHF and the VK sequence RKA, or the VH sequence RHF and the VKsequence RKB. In further embodiments, the humanized anti-CD22 antibodycomprises the VH sequence RHO and the VK sequence RKA, or the VHsequence RHO and the VK sequence RKB. In still other embodiments, thehumanized anti-CD22 antibody comprises the VH sequence RHOv2A and the VKsequence RKA, the VH sequence RHOv2A and the VK sequence RKB, or the VHsequence RHOv2A and the VK sequence RKC. In further embodiments, thehumanized anti-CD22 antibody comprises the VH sequence RHOv2B and the VKsequence RKA, the VH sequence RHOv2B and the VK sequence RKB, or the VHsequence RHOv2B and the VK sequence RKC. In additional embodiments, thehumanized anti-CD22 antibody comprises the VH sequence RHOv2C and the VKsequence RKA, the VH sequence RHOv2C and the VK sequence RKB, or the VHsequence RHOv2C and the VK sequence RKC. In another other embodiment,the humanized anti-CD22 antibody comprises the VH sequence RHOv2D andthe VK sequence RKA, the VH sequence RHOv2D and the VK sequence RKB, orthe VH sequence RHOv2D and the VK sequence RKC. In still anotherembodiment, the humanized anti-CD22 antibody comprises the VH sequenceRHOv2ABCD and the VK sequence RKA, the VH sequence RHOv2ABCD and the VKsequence RKB, or the VH sequence RHOv2ABCD and the VK sequence RKC. In astill further embodiment, the humanized anti-CD22 antibody comprises theVH sequence RHOv2ACD and the VK sequence RKA, or the VH sequenceRHOv2ACD and the VK sequence RKB.

In certain embodiments, a humanized VH or VK derived from the parentalHB22.7 hybridoma is expressed as a chimeric immunoglobulin light chainor a immunoglobulin heavy chain to produce a chimeric anti-CD22antibody. In a particular embodiment, a humanized VH is expressed as achimeric comprising the chVK sequence of (SEQ ID NO:3 or SEQ ID NO:4).In another particular embodiment, a humanized VK is expressed as achimeric comprising the chVH sequence of (SEQ ID NO: SEQ ID NO:1 or SEQID NO:2). In another embodiment, the invention provides a chimericanti-CD22 antibody comprising the chVK sequence of (SEQ ID NO:3 or SEQID NO:4) and the chVH sequence of (SEQ ID NO:1 or SEQ ID NO:2).

In certain embodiments, the humanized VH further comprises a leadersequence which is selected, for example, on the basis of sequencehomology to the leader associated with the native human FW acceptor VH.In one embodiment, a leader is selected based on the basis of sequencehomology to the leader associated with the VH expressed by HB22.7hybridoma. High homology leader sequences are embodiments of theinvention.

In certain embodiments, the humanized VL further comprises a leadersequence which is selected on the basis of sequence homology to theleader associated with the native human FW acceptor VL. In oneembodiment, a leader is selected based on the basis of sequence homologyto the leader associated with the VL expressed by HB22.7 hybridoma. Highhomology leader sequences are used in certain embodiments of theinvention.

In a particular embodiment, the humanized VH further comprises a leadersequence MKSQTQVFVFLLLCVSGAHG (SEQ ID NO:68) selected from the leaderpeptide of the mouse PCG-1 VH gene, or the leader sequenceMDTLCSTLLLLTIPSWVLS (SEQ ID NO:69) selected from the leader peptide ofthe human VH2-05 gene, or the leader peptide MEFGLSWVFLVALLRGVQC (SEQ IDNO:70) selected from the leader peptide of the human VH3-30 gene.

In another embodiment, the humanized VL further comprises a leadersequence MKSQTQVFVFLLLCVSGAHG (SEQ ID NO:71) selected from the leaderpeptide of the mouse SK/CamRK VH gene, or the leader sequenceMDMRVPAQLLGLLQLWLSGARC (SEQ ID NO:72) selected from the leader peptideof the human DPK018 VH gene.

In one embodiment, the humanized anti-CD22 monoclonal antibody comprisesa VH and a VK, wherein the VH comprises the four framework regions, FW1,FW2, FW3, and FW4 of the sequence designated AJ556657 (SEQ ID NO:40 and41) (Colombo, M. M. et al., (2003) Eur. J. Immunol. 33:3422-3438); andthe three VH CDR sequences of the HB22.7 antibody, CDR1 (SEQ ID NO:62),CDR2 (SEQ ID NO:63), and CDR3 (SEQ ID NO:64); and the VK comprises thefour framework regions, FW1, FW2, FW3, and FW4, of the sequencedesignated AJ388641 CDRs with predicted VL clone 47 FW regions (SEQ IDNO:30 and 31) (Welschof, M. et al., (1995) J. Immunol. Methods179:203-214); and the three VK CDR1 (SEQ ID NO:65), CDR2 (SEQ ID NO:66),and CDR3 (SEQ ID NO:67). In one embodiment, this antibody furthercomprises one or more of the following VH and VK framework mutations:the VH mutations selected from the group consisting of F29L, D30S, T49G,and F67L; and the VK mutations selected from the group consisting ofS60D, S67Y and Y87F. In one embodiment, the VH framework regions containeach of the point mutations F29L, D30S, T49G, and F67L; and the VKframework comprises each of the point mutations S60D, S67Y and Y87F. Inanother embodiment, the VH framework regions contain only the D30S pointmutation and the VK framework comprises each of the point mutationsS60D, S67Y and Y87F.

The present invention also provides polynucleotide sequences encodingthe VH and VK framework regions and CDRs of the antibodies of theinvention as well as expression vectors for their efficient expressionin mammalian cells.

The present invention also relates to a method of treating a B cellmalignancy in a human comprising administering to a human in needthereof, a human, humanized or chimeric anti-CD22 antibody of theinvention, particularly a human, humanized or chimeric anti-CD22antibody that mediates human antibody-dependent cell-mediatedcytotoxicity (ADCC), complement-dependent cell-mediated cytotoxicity(CDC), and/or apoptosis in an amount sufficient to deplete circulating Bcells. In a particular aspect, the present invention also concernsmethods of treating a B cell malignancy in a human comprisingadministration of a therapeutically effective regimen of a human,humanized, or chimeric anti-CD22 antibody of the invention, which is ofthe IgG1 or IgG3 human isotype. In another aspect, the present inventionalso concerns methods of treating a B cell malignancy in a humancomprising administration of a therapeutically effective regimen of ahuman, humanized, or chimeric anti-CD22 antibody of the invention, whichis of the IgG2 or IgG4 human isotype.

The present invention further relates to a method of treating anautoimmune disease or disorder in a human comprising administering to ahuman in need thereof a human, humanized, or chimeric anti-CD22 antibodyof the invention that mediates human ADCC, CDC, and/or apoptosis in anamount sufficient to deplete circulating B cells. In a particularaspect, the present invention also concerns methods of treatingautoimmune disorders comprising administration of a therapeuticallyeffective regimen of a human, humanized, or chimeric anti-CD22 antibodyof the invention, which is of the IgG1 or IgG3 human isotype.

The present invention also provides methods for treating or preventinghumoral rejection in a human transplant recipient in need thereofcomprising administering to the recipient a human, humanized, orchimeric anti-CD22 antibody of the invention in an amount sufficient todeplete circulating B cells, or circulating immunoglobulin, or both. Inother embodiments, the invention provides methods for preventing graftrejection or graft versus host disease in a human transplant recipientin need thereof comprising contacting a graft prior to transplantationwith an amount of a human, humanized, or chimeric anti-CD22 antibody ofthe invention sufficient to deplete B cells from the graft.

5.1. Production of Humanized Anti-CD22 Antibodies

The humanized antibodies provided by the invention can be produced usinga variety of techniques known in the art, including, but not limited to,CDR-grafting (see e.g., European Patent No. EP 239,400; InternationalPublication No. WO 91/09967; and U.S. Pat. Nos. 5,225,539, 5,530,101,and 5,585,089, each of which is incorporated herein in its entirety byreference), veneering or resurfacing (see, e.g., European Patent Nos. EP592,106 and EP 519,596; Padlan, 1991, Molecular Immunology28(4/5):489-498; Studnicka et al., 1994, Protein Engineering,7(6):805-814; and Roguska et al., 1994, Proc. Natl. Acad. Sci.,91:969-973, each of which is incorporated herein by its entirety byreference), chain shuffling (see, e.g., U.S. Pat. No. 5,565,332, whichis incorporated herein in its entirety by reference), and techniquesdisclosed in, e.g., U.S. Pat. No. 6,407,213, U.S. Pat. No. 5,766,886,International Publication No. WO 9317105, Tan et al., J. Immunol.,169:1119-25 (2002), Caldas et al., Protein Eng., 13(5):353-60 (2000),Morea et al., Methods, 20(3):267-79 (2000), Baca et al., J. Biol. Chem.,272(16):10678-84 (1997), Roguska et al., Protein Eng., 9(10):895-904(1996), Couto et al., Cancer Res., 55 (23 Supp):5973s-5977s (1995),Couto et al., Cancer Res., 55(8):1717-22 (1995), Sandhu J S, Gene,150(2):409-10 (1994), and Pedersen et al., J. Mol. Biol., 235(3):959-73(1994), each of which is incorporated herein in its entirety byreference. Often, FW residues in the FW regions will be substituted withthe corresponding residue from the CDR donor antibody to alter,preferably improve, antigen binding. These FW substitutions areidentified by methods well-known in the art, e.g., by modeling of theinteractions of the CDR and FW residues to identify FW residuesimportant for antigen binding and sequence comparison to identifyunusual FW residues at particular positions. (See, e.g., Queen et al.,U.S. Pat. No. 5,585,089; and Riechmann et al., 1988, Nature, 332:323,which are incorporated herein by reference in their entireties.)

A humanized anti-CD22 antibody has one or more amino acid residuesintroduced into it from a source which is nonhuman. These nonhuman aminoacid residues are often referred to as “import” residues, which aretypically taken from an “import” variable domain. Thus, humanizedantibodies comprise one or more CDRs from nonhuman immunoglobulinmolecules and framework regions from human. Humanization of antibodiesis well-known in the art and can essentially be performed following themethod of Winter and co-workers (Jones et al., Nature, 321:522-525(1986); Riechmann et al., Nature, 332:323-327 (1988); Verhoeyen et al.,Science, 239:1534-1536 (1988)), by substituting rodent CDRs or CDRsequences for the corresponding sequences of a human antibody, i.e.,CDR-grafting (EP 239,400; PCT Publication No. WO 91/09967; and U.S. Pat.Nos. 4,816,567; 6,331,415; 5,225,539; 5,530,101; 5,585,089; 6,548,640,the contents of which are incorporated herein by reference herein intheir entirety). In such humanized chimeric antibodies, substantiallyless than an intact human variable domain has been substituted by thecorresponding sequence from a nonhuman species. In practice, humanizedantibodies are typically human antibodies in which some CDR residues andpossibly some FW residues are substituted by residues from analogoussites in rodent antibodies. Humanization of anti-CD22 antibodies canalso be achieved by veneering or resurfacing (EP 592,106; EP 519,596;Padlan, 1991, Molecular Immunology 28(4/5):489-498; Studnicka et al.,Protein Engineering, 7(6):805-814 (1994); and Roguska et al., Proc.Natl. Acad. Sci., 91:969-973 (1994)) or chain shuffling (U.S. Pat. No.5,565,332), the contents of which are incorporated herein by referenceherein in their entirety.

The choice of human variable domains, both light and heavy, to be usedin making the humanized antibodies is to reduce antigenicity. Accordingto the so-called “best-fit” method, the sequence of the variable domainof a rodent antibody is screened against the entire library of knownhuman variable-domain sequences. The human sequences which are mostclosely related to that of the rodent are then screened for thepresences of specific residues that may be critical for antigen binding,appropriate structural formation and/or stability of the intendedhumanized mAb (Sims et al., J. Immunol., 151:2296 (1993); Chothia etal., J. Mol. Biol., 196:901 (1987), the contents of which areincorporated herein by reference herein in their entirety). Theresulting FW sequences matching the desired criteria are then be used asthe human donor FW regions for the humanized antibody.

Another method uses a particular FW derived from the consensus sequenceof all human antibodies of a particular subgroup of light or heavychains. The same FW may be used for several different humanizedanti-CD22 antibodies (Carter et al., Proc. Natl. Acad. Sci. USA, 89:4285(1992); Presta et al., J. Immunol., 151:2623 (1993), the contents ofwhich are incorporated herein by reference herein in their entirety).

Anti-CD22 antibodies can be humanized with retention of high affinityfor CD22 and other favorable biological properties. According to oneaspect of the invention, humanized antibodies are prepared by a processof analysis of the parental sequences and various conceptual humanizedproducts using three-dimensional models of the parental and humanizedsequences. Three-dimensional immunoglobulin models are commonlyavailable and are familiar to those skilled in the art. Computerprograms are available which illustrate and display probablethree-dimensional conformational structures of selected candidateimmunoglobulin sequences. Inspection of these displays permits analysisof the likely role of the residues in the functioning of the candidateimmunoglobulin sequence, i.e., the analysis of residues that influencethe ability of the candidate immunoglobulin to bind CD22. In this way,FW residues can be selected and combined from the recipient and importsequences so that the desired antibody characteristic, such as increasedaffinity for CD22, is achieved. In general, the CDR residues aredirectly and most substantially involved in influencing antigen binding.

A “humanized” antibody retains a similar antigenic specificity as theoriginal antibody, i.e., in the present invention, the ability to bindhuman CD22 antigen. However, using certain methods of humanization, theaffinity and/or specificity of binding of the antibody for human CD22antigen may be increased using methods of “directed evolution,” asdescribed by Wu et al., J. Mol. Biol., 294:151 (1999), the contents ofwhich are incorporated herein by reference herein in their entirety.

The humanized anti-CD22 antibodies provided by the invention wereconstructed by the selection of distinct human framework regions forgrafting of the HB22.7 complementarity determining regions, or “CDR's”as described in the sections that follow. The invention provides anumber of humanized versions of the mouse HB22.7 antibody as well as achimeric version, designated chHB227.

5.2. Monoclonal Anti-CD22 Antibodies

The monoclonal anti-CD22 antibodies of the invention exhibit bindingspecificity to human CD22 antigen and can preferably mediate human ADCCand/or apoptotic mechanisms. These antibodies can be generated using awide variety of techniques known in the art including the use ofhybridoma, recombinant, and phage display technologies, or a combinationthereof. Antibodies are highly specific, being directed against a singleantigenic site. An engineered anti-CD22 antibody can be produced by anymeans known in the art, including, but not limited to, those techniquesdescribed below and improvements to those techniques. Large-scalehigh-yield production typically involves culturing a host cell thatproduces the engineered anti-CD22 antibody and recovering the anti-CD22antibody from the host cell culture.

5.2.1. Hybridoma Technique

Monoclonal antibodies can be produced using hybridoma techniquesincluding those known in the art and taught, for example, in Harlow etal., Antibodies: A Laboratory Manual, (Cold Spring Harbor LaboratoryPress, 2nd ed. 1988); Hammerling et al., in Monoclonal Antibodies and TCell Hybridomas, 563-681 (Elsevier, N.Y., 1981) (said referencesincorporated by reference in their entireties). For example, in thehybridoma method, a mouse or other appropriate host animal, such as ahamster or macaque monkey, is immunized to elicit lymphocytes thatproduce or are capable of producing antibodies that will specificallybind to the protein used for immunization. Alternatively, lymphocytesmay be immunized in vitro. Lymphocytes then are fused with myeloma cellsusing a suitable fusing agent, such as polyethylene glycol, to form ahybridoma cell (Goding, Monoclonal Antibodies: Principles and Practice,pp. 59-103 (Academic Press, 1986)).

The hybridoma cells thus prepared are seeded and grown in a suitableculture medium that preferably contains one or more substances thatinhibit the growth or survival of the unfused, parental myeloma cells.For example, if the parental myeloma cells lack the enzyme hypoxanthineguanine phosphoribosyl transferase (HGPRT or HPRT), the culture mediumfor the hybridomas typically will include hypoxanthine, aminopterin, andthymidine (HAT medium), which substances prevent the growth ofHGPRT-deficient cells.

Specific embodiments employ myeloma cells that fuse efficiently, supportstable high-level production of antibody by the selectedantibody-producing cells, and are sensitive to a medium such as HATmedium. Among these myeloma cell lines are murine myeloma lines, such asthose derived from MOPC-21 and MPC-11 mouse tumors available from theSalk Institute Cell Distribution Center, San Diego, Calif., USA, andSP-2 or X63-Ag8.653 cells available from the American Type CultureCollection, Rockville, Md., USA. Human myeloma and mouse-humanheteromyeloma cell lines also have been described for the production ofhuman monoclonal antibodies (Kozbor, J. Immunol., 133:3001 (1984);Brodeur et al., Monoclonal Antibody Production Techniques andApplications, pp. 51-63 (Marcel Dekker, Inc., New York, 1987)).

Culture medium in which hybridoma cells are growing is assayed forproduction of monoclonal antibodies directed against the human CD22antigen. Preferably, the binding specificity of monoclonal antibodiesproduced by hybridoma cells is determined by immunoprecipitation or byan in vitro binding assay, such as radioimmunoassay (RIA) orenzyme-linked immunoabsorbent assay (ELISA).

After hybridoma cells are identified that produce antibodies of thedesired specificity, affinity, and/or activity, the clones may besubcloned by limiting dilution procedures and grown by standard methods(Goding, Monoclonal Antibodies: Principles and Practice, pp. 59-103(Academic Press, 1986)). Suitable culture media for this purposeinclude, for example, D-MEM or RPMI 1640 medium. In addition, thehybridoma cells may be grown in vivo as ascites tumors in an animal.

The monoclonal antibodies secreted by the subclones are suitablyseparated from the culture medium, ascites fluid, or serum byconventional immunoglobulin purification procedures such as, forexample, protein A-Sepharose, hydroxylapatite chromatography, gelelectrophoresis, dialysis, or affinity chromatography.

5.2.2. Recombinant DNA Techniques

DNA encoding the anti-CD22 antibodies of the invention is readilyisolated and sequenced using conventional procedures (e.g., by usingoligonucleotide probes that are capable of binding specifically to genesencoding the heavy and light chains of the anti-CD22 antibodies). Thehybridoma cells serve as a source of such DNA. Once isolated, the DNAmay be placed into expression vectors, which are then transfected intohost cells such as E. coli cells, simian COS cells, Chinese hamsterovary (CHO) cells, or myeloma cells that do not otherwise produceimmunoglobulin protein, to obtain the synthesis of anti-CD22 antibodiesin the recombinant host cells.

In phage display methods, functional antibody domains are displayed onthe surface of phage particles which carry the polynucleotide sequencesencoding them. In particular, DNA sequences encoding V_(H) and V_(L)domains are amplified from animal cDNA libraries (e.g., human or murinecDNA libraries of affected tissues). The DNA encoding the V_(H) andV_(L) domains are recombined together with an scFv linker by PCR andcloned into a phagemid vector. The vector is electroporated in E. coliand the E. coli is infected with helper phage. Phage used in thesemethods are typically filamentous phage including fd and M13 and theV_(H) and V_(L) domains are usually recombinantly fused to either thephage gene III or gene VIII. Phage expressing an antigen-binding domainthat binds to a particular antigen can be selected or identified withantigen, e.g., using labeled antigen or antigen bound or captured to asolid surface or bead. Examples of phage display methods that can beused to make the antibodies of the present invention include thosedisclosed in Brinkman et al., 1995, J. Immunol. Methods, 182:41-50; Ameset al., 1995, J. Immunol. Methods, 184:177-186; Kettleborough et al.,1994, Eur. J. Immunol., 24:952-958; Persic et al., 1997, Gene, 187:9-18;Burton et al., 1994, Advances in Immunology, 57:191-280; InternationalApplication No. PCT/GB91/O1 134; International Publication Nos. WO90/02809, WO 91/10737, WO 92/01047, WO 92/18619, WO 93/11236, WO95/15982, WO 95/20401, and WO97/13844; and U.S. Pat. Nos. 5,698,426,5,223,409, 5,403,484, 5,580,717, 5,427,908, 5,750,753, 5,821,047,5,571,698, 5,427,908, 5,516,637, 5,780,225, 5,658,727, 5,733,743, and5,969,108; each of which is incorporated herein by reference in itsentirety.

As described in the above references, after phage selection, theantibody coding regions from the phage can be isolated and used togenerate whole antibodies, including human antibodies, or any otherdesired antigen-binding fragment, and expressed in any desired host,including mammalian cells, insect cells, plant cells, yeast, andbacteria, e.g., as described below. Techniques to recombinantly produceFab, Fab′ and F(ab′)₂ fragments can also be employed using methods knownin the art such as those disclosed in PCT Publication No. WO 92/22324;Mullinax et al., 1992, BioTechniques, 12(6):864-869; Sawai et al., 1995,AJRI, 34:26-34; and Better et al., 1988, Science, 240:1041-1043 (saidreferences incorporated by reference in their entireties).

Antibodies may be isolated from antibody phage libraries generated usingthe techniques described in McCafferty et al., Nature, 348:552-554(1990). Clackson et al., Nature, 352:624-628 (1991). Marks et al., J.Mol. Biol., 222:581-597 (1991) describe the isolation of murine andhuman antibodies, respectively, using phage libraries. Chain shufflingcan be used in the production of high affinity (nM range) humanantibodies (Marks et al., Bio/Technology, 10:779-783 (1992)), as well ascombinatorial infection and in vivo recombination as a strategy forconstructing very large phage libraries (Waterhouse et al., Nuc. Acids.Res., 21:2265-2266 (1993)). Thus, these techniques are viablealternatives to traditional monoclonal antibody hybridoma techniques forisolation of anti-CD22 antibodies.

To generate whole antibodies, PCR primers including VH or VL nucleotidesequences, a restriction site, and a flanking sequence to protect therestriction site can be used to amplify the VH or VL sequences in scFvclones. Utilizing cloning techniques known to those of skill in the art,the PCR amplified VH domains can be cloned into vectors expressing aheavy chain constant region, e.g., the human gamma 4 constant region,and the PCR amplified VL domains can be cloned into vectors expressing alight chain constant region, e.g., human kappa or lambda constantregions. Preferably, the vectors for expressing the VH or VL domainscomprise an EF-1α promoter, a secretion signal, a cloning site for thevariable domain, constant domains, and a selection marker such asneomycin. The VH and VL domains may also be cloned into one vectorexpressing the necessary constant regions. The heavy chain conversionvectors and light chain conversion vectors are then co-transfected intocell lines to generate stable or transient cell lines that expressfull-length antibodies, e.g., IgG, using techniques known to those ofskill in the art.

The DNA also may be modified, for example, by substituting the codingsequence for human heavy and light chain constant domains in place ofthe homologous murine sequences (U.S. Pat. No. 4,816,567; Morrison etal., Proc. Natl. Acad. Sci. USA, 81:6851 (1984)), or by covalentlyjoining to the immunoglobulin coding sequence all or part of the codingsequence for a non-immunoglobulin polypeptide.

5.3. Chimeric Antibodies

The anti-CD22 antibodies herein specifically include chimeric antibodies(immunoglobulins) in which a portion of the heavy and/or light chain isidentical with or homologous to corresponding sequences in antibodiesderived from a particular species or belonging to a particular antibodyclass or subclass, while another portion of the chain(s) is identicalwith or homologous to corresponding sequences in antibodies derived fromanother species or belonging to another antibody class or subclass, aswell as fragments of such antibodies, so long as they exhibit thedesired biological activity (U.S. Pat. No. 4,816,567; Morrison et al.,Proc. Natl. Acad. Sci. USA, 81:6851-6855 (1984)). Chimeric antibodies ofinterest herein include “primatized” antibodies comprising variabledomain antigen-binding sequences derived from a nonhuman primate (e.g.,Old World Monkey, such as baboon, rhesus or cynomolgus monkey) and humanconstant region sequences (U.S. Pat. No. 5,693,780).

The present invention provides for antibodies that have a high bindingaffinity for the hCD22 antigen. In a specific embodiment, an antibody ofthe present invention has an association rate constant or k_(on) rate(antibody (Ab)+antigen (Ag)^(k) ^(on) →Ab−Ag) of at least 2×10⁵ M⁻¹s⁻¹,at least 5×10⁵ M⁻¹s⁻¹, at least 10⁶ M⁻¹s⁻¹, at least 5×10⁶ M⁻¹s⁻¹, atleast 10⁷ M⁻¹s⁻¹, at least 5×10⁷ M⁻¹s⁻¹, or at least 10⁸ M⁻¹s⁻¹. In apreferred embodiment, an antibody of the present invention has a k_(on)of at least 2×10⁵ M⁻¹s⁻¹, at least 5×10⁵ M⁻¹s⁻¹, at least 10⁶ M⁻¹s⁻¹, atleast 5×10⁶ M⁻¹s⁻¹, at least 10⁷ M⁻¹s⁻¹, at least 5×10⁷ M⁻¹s⁻¹, or atleast 10⁸ M⁻¹s⁻¹. In another embodiment, an antibody of the inventionhas a k_(off) rate ((Ab−Ag)^(k) ^(off) →antibody (Ab)+antigen) of lessthan 10⁻¹s⁻¹, less than 5×10⁻¹s⁻¹, less than 10⁻² s⁻¹, less than 5×10⁻²s⁻¹, less than 10⁻³ s⁻¹, less than 5×10⁻³ s⁻¹, less than 10⁻⁴s⁻¹, lessthan 5×10⁴ s⁻¹, less than 10⁻⁵ s⁻¹, less than 5×10⁻⁵ s⁻¹, less than 10⁻⁶s⁻¹, less than 5×10⁻⁶ s⁻¹, less than 10⁻⁷ s⁻¹, less than 5×⁻⁷s⁻¹, lessthan 10⁻⁸ s⁻¹, less than 5×10⁻⁸s⁻¹, less than 10⁻⁹ s⁻¹, less than 5×10⁻⁹s⁻¹, or less than 10⁻¹⁰ s⁻¹. In a preferred embodiment, an antibody ofthe invention has a k_(on) of less than 5×10⁻⁴ s⁻¹, less than 10⁻⁵ s⁻¹,less than 5×10⁻⁵ s⁻¹, less than 10⁻⁶ s⁻¹, less than 5×10⁻⁶ s⁻¹, lessthan 10⁻⁷ s⁻¹, less than 5×10⁻⁷ s⁻¹, less than 10⁻⁸ s⁻¹, less than5×10⁻⁸ s⁻¹, less than 10⁻⁹ s⁻¹, less than 5×10⁻⁹ s⁻¹ or less than10¹⁰s⁻¹.

In another embodiment, an antibody of the invention has an affinityconstant or K_(a)(k_(on)/k_(off)) of at least 10² M⁻¹, at least 5×10²M⁻¹, at least 10³ M⁻¹, at least 5×10³ M⁻¹, at least 10⁴ M⁻¹, at least5×10⁴ M⁻¹, at least 10⁵ M⁻¹, at least 5×10⁵ M⁻¹, at least 10⁶ M⁻¹, atleast 5×10⁶ M⁻¹, at least 10⁷ M⁻¹, at least 5×10⁷ M⁻¹, at least 10⁸ M⁻¹,at least 5×10⁸ M⁻¹, at least 10⁹ M⁻¹, at least 5×10⁹ M⁻¹, at least 10¹⁰M⁻¹, at least 5×10¹⁰ M⁻¹, at least 10¹¹ M⁻¹, at least 5×10¹¹ M⁻¹, atleast 10¹² M⁻¹, at least 5×10¹² M⁻¹, at least 10¹³ M⁻¹, at least 5×10¹³M⁻¹, at least 10¹⁴ M⁻¹, at least 5×10¹⁴ M⁻¹, at least 10¹⁵ M⁻¹, or atleast 5×10⁻¹⁵ M⁻¹. In yet another embodiment, an antibody has adissociation constant or K_(d) (k_(off)/k_(on)) of less than 10⁻² M,less than 5×10⁻² M, less than 10⁻³ M, less than 5×10⁻³ M, less than 10⁴M, less than 5×10⁻⁴ M, less than 10⁻⁵ M, less than 5×10⁻⁵ M, less than10⁻⁶ M, less than 5×10⁻⁶ M, less than 10⁻⁷ M, less than 5×10⁻⁷ M, lessthan 10⁻⁸ M, less than 5×10⁻⁸ M, less than 10⁻⁹ M, less than 5×10⁻⁹ M,less than 10⁻¹⁰ M, less than 5×10⁻¹⁰ M, less than 10⁻¹¹ M, less than5×10⁻¹¹ M, less than 10⁻¹² M, less than 5×10⁻¹² M, less than 10⁻¹³ M,less than 5×10⁻¹³ M, less than 10⁻¹⁴ M, less than 5×10⁻¹⁴ M, less than10⁻¹⁵ M, or less than 5×10⁻¹⁵ M.

The antibodies used in accordance with the methods of the inventionimmunospecifically bind to hCD22 and have a dissociation constant(K_(D)) of less than 3000 pM, less than 2500 pM, less than 2000 pM, lessthan 1500 pM, less than 1000 pM, less than 750 pM, less than 500 pM,less than 250 pM, less than 200 pM, less than 150 pM, less than 100 pM,less than 75 pM as assessed using an described herein or known to one ofskill in the art (e.g., a BIAcore assay) (Biacore International AB,Uppsala, Sweden). In a specific embodiment, the antibodies used inaccordance with the methods of the invention immunospecifically bind tohuman CD22 antigen and have a dissociation constant (K_(D)) of between25 to 3400 pM, 25 to 3000 pM, 25 to 2500 pM, 25 to 2000 pM, 25 to 1500pM, 25 to 1000 pM, 25 to 750 pM, 25 to 500 pM, 25 to 250 pM, 25 to 100pM, 25 to 75 pM, 25 to 50 pM as assessed using methods described hereinor known to one of skill in the art (e.g., a BIAcore assay). In anotherembodiment, the antibodies used in accordance with the methods of theinvention immunospecifically bind to hCD22 and have a dissociationconstant (K_(D)) of 500 pM, preferably 100 pM, more preferably 75 pM andmost preferably 50 pM as assessed using an described herein or known toone of skill in the art (e.g., a BIAcore assay).

5.4. Altered/Mutant Antibodies

The anti-CD22 antibodies of the compositions and methods of theinvention can be mutant antibodies. As used herein, “antibody mutant” or“altered antibody” refers to an amino acid sequence variant of ananti-CD22 antibody wherein one or more of the amino acid residues of ananti-CD22 antibody have been modified. The modifications to the aminoacid sequence of the anti-CD22 antibody, include modifications to thesequence to improve affinity or avidity of the antibody for its antigen,and/or modifications to the Fc portion of the antibody to improve or tomodulate effector function.

The present invention, therefore relates to the human, humanized, andchimeric anti-CD22 antibodies disclosed herein as well as altered/mutantderivatives thereof exhibiting improved human CD22 bindingcharacteristics; e.g. including altered association constants K_(ON),dissociation constants K_(OFF), and/or altered equilibrium constant orbinding affinity, K_(a). In certain embodiments the K_(a). of anantibody of the present invention, or an altered/mutant derivativethereof, for human CD22 is no more than about 10⁻⁶M, 10⁻⁷M, 10⁻⁸M, or a10⁻⁹M. Methods and reagents suitable for determination of such bindingcharacteristics of an antibody of the present invention, or analtered/mutant derivative thereof, are known in the art and/or arecommercially available (se above and, e.g., U.S. Pat. No. 6,849,425,U.S. Pat. No. 6,632,926, U.S. Pat. No. 6,294,391, and U.S. Pat. No.6,143,574, each of which is hereby incorporated by reference in itsentirety). Moreover, equipment and software designed for such kineticanalyses are commercially available (e.g. Biacore® A100, and Biacore®2000 instruments; Biacore International AB, Uppsala, Sweden).

The modifications may be made to any known anti-CD22 antibodies oranti-CD22 antibodies identified as described herein. Such alteredantibodies necessarily have less than 100% sequence identity orsimilarity with a known anti-CD22 antibody. In certain embodiments, thealtered antibody will have an amino acid sequence that is within therange of from about 25% to about 95% identical or similar to the aminoacid sequence of either the heavy or light chain variable domain of ananti-CD22 antibody of the invention. In particular embodiments, thealtered antibody will have an amino acid sequence having at least 25%,35%, 45%, 55%, 65%, or 75% amino acid sequence identity or similaritywith the amino acid sequence of either the heavy or light chain variabledomain of an anti-CD22 antibody of the invention, more preferably atleast 80%, more preferably at least 85%, more preferably at least 90%,and most preferably at least 95%. In another embodiment, the alteredantibody will have an amino acid sequence having at least 25%, 35%, 45%,55%, 65%, or 75% amino acid sequence identity or similarity with theamino acid sequence of the heavy chain CDR1, CDR2, or CDR3 of ananti-CD22 antibody of the invention, more preferably at least 80%, morepreferably at least 85%, more preferably at least 90%, and mostpreferably at least 95%. In one embodiment, the altered antibody willmaintain human CD22 binding capability. In certain embodiments,anti-CD22 antibodies of the invention comprises a VH that is at least orabout 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70%,75%, 80%, 85%, 90%, 95% or more identical to an amino acid sequence ofHB227 VH (SEQ ID NO:7), HB227-(V2-70+IC4) (SEQ ID NO:13), HB227-VH46898(SEQ ID NO:15), HB227RHB (SEQ ID NO:17), HB227RHC (SEQ ID NO:19),HB227RHD (SEQ ID NO:21), HB227RHE (SEQ ID NO:23), HB227RHF (SEQ IDNO:25), HB227-AJ556657 (SEQ ID NO:43), HB227RHO-V3-30 backmutated (SEQID NO:47), HB227RHOv2-VH2-50 (SEQ ID NO:49), HB227RHOv2A VH2-50 (SEQ IDNO:51), HB227RHOv2B-VH2-50 (SEQ ID NO:53), HB227RHOv2C-VH2-50 (SEQ IDNO:55), HB227RHOv2D-VH2-50 (SEQ ID NO:57), HB227RHOv2ACD-VH2-50 (SEQ IDNO:59), or HB227RHOv2-VH2-50 (SEQ ID NO:61) (see FIGS. 5A-G and 13A-G).

In certain embodiments, the anti-CD22 antibody of the inventioncomprises a VL that is at least or about 10%, 15%, 20%, 25%, 30%, 35%,40%, 45%, 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, 90%, 95% or moreidentical to an amino acid sequence of HB227 VK (SEQ ID NO:27),HB227-Clone 47 (SEQ ID NO:33), HB227RKA (SEQ ID NO:35), HB227RKB (SEQ IDNO:37), or HB227RKC (SEQ ID NO:39) (see FIG. 7A-D).

The mouse hybridoma HB22.7 producing anti-CD22 antibodies has beendeposited under ATCC deposit nos. HB11347 deposited on May 14, 1993.

Identity or similarity with respect to a sequence is defined herein asthe percentage of amino acid residues in the candidate sequence that areidentical (i.e., same residue) or similar (i.e., amino acid residue fromthe same group based on common side-chain properties, see below) withanti-CD22 antibody residues, after aligning the sequences andintroducing gaps, if necessary, to achieve the maximum percent sequenceidentity. None of N-terminal, C-terminal, or internal extensions,deletions, or insertions into the antibody sequence outside of thevariable domain shall be construed as affecting sequence identity orsimilarity.

“% identity,” as known in the art, is a measure of the relationshipbetween two polynucleotides or two polypeptides, as determined bycomparing their nucleotide or amino acid sequences, respectively. Ingeneral, the two sequences to be compared are aligned to give a maximumcorrelation between the sequences. The alignment of the two sequences isexamined and the number of positions giving an exact amino acid ornucleotide correspondence between the two sequences determined, dividedby the total length of the alignment and multiplied by 100 to give a %identity figure. This % identity figure may be determined over the wholelength of the sequences to be compared, which is particularly suitablefor sequences of the same or very similar length and which are highlyhomologous, or over shorter defined lengths, which is more suitable forsequences of unequal length or which have a lower level of homology.

For example, sequences can be aligned with the software CLUSTALW underUnix which generates a file with an “.aln” extension, this file can thenbe imported into the Bioedit program (Hall, T. A. 1999, BioEdit: auser-friendly biological sequence alignment editor and analysis programfor Windows 95/98/NT. Nucl. Acids. Symp. Ser. 41:95-98) which opens the.aln file. In the Bioedit window, one can choose individual sequences(two at a time) and alignment them. This method allows for comparison ofthe entire sequence.

Methods for comparing the identity of two or more sequences arewell-known in the art. Thus for instance, programs are available in theWisconsin Sequence Analysis Package, version 9.1 (Devereux J. et al.,Nucleic Acids Res., 12:387-395, 1984, available from Genetics ComputerGroup, Madison, Wis., USA). The determination of percent identitybetween two sequences can be accomplished using a mathematicalalgorithm. For example, the programs BESTFIT and GAP, may be used todetermine the % identity between two polynucleotides and the % identitybetween two polypeptide sequences. BESTFIT uses the “local homology”algorithm of Smith and Waterman (Advances in Applied Mathematics,2:482-489, 1981) and finds the best single region of similarity betweentwo sequences. BESTFIT is more suited to comparing two polynucleotide ortwo polypeptide sequences which are dissimilar in length, the programassuming that the shorter sequence represents a portion of the longer.In comparison, GAP aligns two sequences finding a “maximum similarity”according to the algorithm of Neddleman and Wunsch (J. Mol. Biol.,48:443-354, 1970). GAP is more suited to comparing sequences which areapproximately the same length and an alignment is expected over theentire length. Preferably the parameters “Gap Weight” and “LengthWeight” used in each program are 50 and 3 for polynucleotides and 12 and4 for polypeptides, respectively. Preferably % identities andsimilarities are determined when the two sequences being compared areoptimally aligned.

Other programs for determining identity and/or similarity betweensequences are also known in the art, for instance the BLAST family ofprograms (Karlin & Altschul, 1990, Proc. Natl. Acad. Sci. USA,87:2264-2268, modified as in Karlin & Altschul, 1993, Proc. Natl. Acad.Sci. USA, 90:5873-5877, available from the National Center forBiotechnology Information (NCB), Bethesda, Md., USA and accessiblethrough the home page of the NCBI at www.ncbi.nlm.nih.gov). Theseprograms are non-limiting examples of a mathematical algorithm utilizedfor the comparison of two sequences. Such an algorithm is incorporatedinto the NBLAST and XBLAST programs of Altschul et al., 1990, J. Mol.Biol., 215:403-410. BLAST nucleotide searches can be performed with theNBLAST program, score=100, wordlength=12 to obtain nucleotide sequenceshomologous to a nucleic acid molecule encoding all or a portion if ananti-CD22 antibody of the invention. BLAST protein searches can beperformed with the XBLAST program, score=50, wordlength=3 to obtainamino acid sequences homologous to a protein molecule of the invention.To obtain gapped alignments for comparison purposes, Gapped BLAST can beutilized as described in Altschul et al., 1997, Nucleic Acids Res.,25:3389-3402. Alternatively, PSI-Blast can be used to perform aniterated search which detects distant relationships between molecules(Id.). When utilizing BLAST, Gapped BLAST, and PSI-Blast programs, thedefault parameters of the respective programs (e.g., XBLAST and NBLAST)can be used. See, http://www.ncbi.nlm.nih.gov. Another, non-limitingexample of a mathematical algorithm utilized for the comparison ofsequences is the algorithm of Myers and Miller, 1988, CABIOS 4:11-17.Such an algorithm is incorporated into the ALIGN program (version 2.0)which is part of the GCG sequence alignment software package. Whenutilizing the ALIGN program for comparing amino acid sequences, a PAM120weight residue table, a gap length penalty of 12, and a gap penalty of 4can be used.

Another non-limiting example of a program for determining identityand/or similarity between sequences known in the art is FASTA (PearsonW. R. and Lipman D. J., Proc. Natl. Acad. Sci. USA, 85:2444-2448, 1988,available as part of the Wisconsin Sequence Analysis Package).Preferably the BLOSUM62 amino acid substitution matrix (Henikoff S. andHenikoff J. G., Proc. Natl. Acad. Sci. USA, 89:10915-10919, 1992) isused in polypeptide sequence comparisons including where nucleotidesequences are first translated into amino acid sequences beforecomparison.

Yet another non-limiting example of a program known in the art fordetermining identity and/or similarity between amino acid sequences isSeqWeb Software (a web-based interface to the GCG Wisconsin Package: Gapprogram) which is utilized with the default algorithm and parametersettings of the program: blosum62, gap weight 8, length weight 2.

The percent identity between two sequences can be determined usingtechniques similar to those described above, with or without allowinggaps. In calculating percent identity, typically exact matches arecounted.

Preferably the program BESTFIT is used to determine the % identity of aquery polynucleotide or a polypeptide sequence with respect to apolynucleotide or a polypeptide sequence of the present invention, thequery and the reference sequence being optimally aligned and theparameters of the program set at the default value.

To generate an altered antibody, one or more amino acid alterations(e.g., substitutions) are introduced in one or more of the hypervariableregions of the species-dependent antibody. Alternatively, or inaddition, one or more alterations (e.g., substitutions) of frameworkregion residues may be introduced in an anti-CD22 antibody where theseresult in an improvement in the binding affinity of the antibody mutantfor the antigen from the second mammalian species. Examples of frameworkregion residues to modify include those which non-covalently bindantigen directly (Amit et al., Science, 233:747-753 (1986)); interactwith/effect the conformation of a CDR (Chothia et al., J. Mol. Biol.,196:901-917 (1987)); and/or participate in the V_(L)-V_(H) interface (EP239 400B1). In certain embodiments, modification of one or more of suchframework region residues results in an enhancement of the bindingaffinity of the antibody for the antigen from the second mammalianspecies. For example, from about one to about five framework residuesmay be altered in this embodiment of the invention. Sometimes, this maybe sufficient to yield an antibody mutant suitable for use inpreclinical trials, even where none of the hypervariable region residueshave been altered. Normally, however, an altered antibody will compriseadditional hypervariable region alteration(s).

The hypervariable region residues which are altered may be changedrandomly, especially where the starting binding affinity of an anti-CD22antibody for the antigen from the second mammalian species is such thatsuch randomly produced altered antibody can be readily screened.

One useful procedure for generating such an altered antibody is called“alanine scanning mutagenesis” (Cunningham and Wells, Science,244:1081-1085 (1989)). Here, one or more of the hypervariable regionresidue(s) are replaced by alanine or polyalanine residue(s) to affectthe interaction of the amino acids with the antigen from the secondmammalian species. Those hypervariable region residue(s) demonstratingfunctional sensitivity to the substitutions then are refined byintroducing additional or other mutations at or for the sites ofsubstitution. Thus, while the site for introducing an amino acidsequence variation is predetermined, the nature of the mutation per seneed not be predetermined. The Ala-mutants produced this way arescreened for their biological activity as described herein.

Another procedure for generating such an altered antibody involvesaffinity maturation using phage display (Hawkins et al., J. Mol. Biol.,254:889-896 (1992) and Lowman et al., Biochemistry, 30(45):10832-10837(1991)). Briefly, several hypervariable region sites (e.g., 6-7 sites)are mutated to generate all possible amino acid substitutions at eachsite. The antibody mutants thus generated are displayed in a monovalentfashion from filamentous phage particles as fusions to the gene IIIproduct of M13 packaged within each particle. The phage-displayedmutants are then screened for their biological activity (e.g., bindingaffinity) as herein disclosed.

Mutations in antibody sequences may include substitutions, deletions,including internal deletions, additions, including additions yieldingfusion proteins, or conservative substitutions of amino acid residueswithin and/or adjacent to the amino acid sequence, but that result in a“silent” change, in that the change produces a functionally equivalentanti-CD22 antibody. Conservative amino acid substitutions may be made onthe basis of similarity in polarity, charge, solubility, hydrophobicity,hydrophilicity, and/or the amphipathic nature of the residues involved.For example, non-polar (hydrophobic) amino acids include alanine,leucine, isoleucine, valine, proline, phenylalanine, tryptophan, andmethionine; polar neutral amino acids include glycine, serine,threonine, cysteine, tyrosine, asparagine, and glutamine; positivelycharged (basic) amino acids include arginine, lysine, and histidine; andnegatively charged (acidic) amino acids include aspartic acid andglutamic acid. In addition, glycine and proline are residues that caninfluence chain orientation. Non-conservative substitutions will entailexchanging a member of one of these classes for another class.Furthermore, if desired, non-classical amino acids or chemical aminoacid analogs can be introduced as a substitution or addition into theantibody sequence. Non-classical amino acids include, but are notlimited to, the D-isomers of the common amino acids, α-amino isobutyricacid, 4-aminobutyric acid, Abu, 2-amino butyric acid, γ-Abu, ε-Ahx,6-amino hexanoic acid, Aib, 2-amino isobutyric acid, 3-amino propionicacid, ornithine, norleucine, norvaline, hydroxyproline, sarcosine,citrulline, cysteic acid, t-butylglycine, t-butylalanine, phenylglycine,cyclohexylalanine, β-alanine, fluoro-amino acids, designer amino acidssuch as β-methyl amino acids, Cα-methyl amino acids, Nα-methyl aminoacids, and amino acid analogs in general.

In another embodiment, the sites selected for modification are affinitymatured using phage display (see above).

Any technique for mutagenesis known in the art can be used to modifyindividual nucleotides in a DNA sequence, for purposes of making aminoacid substitution(s) in the antibody sequence, or for creating/deletingrestriction sites to facilitate further manipulations. Such techniquesinclude, but are not limited to, chemical mutagenesis, in vitrosite-directed mutagenesis (Kunkel, Proc. Natl. Acad. Sci. USA, 82:488(1985); Hutchinson, C. et al., J. Biol. Chem., 253:6551 (1978)),oligonucleotide-directed mutagenesis (Smith, Ann. Rev. Genet.,19:423-463 (1985); Hill et al., Methods Enzymol., 155:558-568 (1987)),PCR-based overlap extension (Ho et al., Gene, 77:51-59 (1989)),PCR-based megaprimer mutagenesis (Sarkar et al., Biotechniques,8:404-407 (1990)), etc. Modifications can be confirmed bydouble-stranded dideoxy DNA sequencing.

In certain embodiments of the invention the anti-CD22 antibodies can bemodified to produce fusion proteins; i.e., the antibody, or a fragmentfused to a heterologous protein, polypeptide or peptide. In certainembodiments, the protein fused to the portion of an anti-CD22 antibodyis an enzyme component of Antibody-Directed Enzyme Prodrug Therapy(ADEPT). Examples of other proteins or polypeptides that can beengineered as a fusion protein with an anti-CD22 antibody include, butare not limited to toxins such as ricin, abrin, ribonuclease, DNase I,Staphylococcal enterotoxin-A, pokeweed anti-viral protein, gelonin,diphtherin toxin, Pseudomonas exotoxin, and Pseudomonas endotoxin. See,for example, Pastan et al., Cell, 47:641 (1986), and Goldenberg et al.,Cancer Journal for Clinicians, 44:43 (1994). Enzymatically active toxinsand fragments thereof which can be used include diphtheria A chain,non-binding active fragments of diphtheria toxin, exotoxin A chain (fromPseudomonas aeruginosa), ricin A chain, abrin A chain, modeccin A chain,alpha-sarcin, Aleurites fordii proteins, dianthin proteins, Phytolacaamericana proteins (PAPI, PAPII, and PAP-S), momordica charantiainhibitor, curcin, crotin, sapaonaria officinalis inhibitor, gelonin,mitogellin, restrictocin, phenomycin, enomycin and the tricothecenes.See, for example, WO 93/21232 published Oct. 28, 1993.

Additional fusion proteins may be generated through the techniques ofgene-shuffling, motif-shuffling, exon-shuffling, and/or codon-shuffling(collectively referred to as “DNA shuffling”). DNA shuffling may beemployed to alter the activities of SYNAGIS® or fragments thereof (e.g.,an antibody or a fragment thereof with higher affinities and lowerdissociation rates). See, generally, U.S. Pat. Nos. 5,605,793;5,811,238; 5,830,721; 5,834,252; and 5,837,458, and Patten et al., 1997,Curr. Opinion Biotechnol., 8:724-33 Harayama, 1998, Trends Biotechnol.16(2):76-82; Hansson et al., 1999, J. Mol. Biol., 287:265-76; andLorenzo and Blasco, 1998, Biotechniques 24(2):308-313 (each of thesepatents and publications are hereby incorporated by reference in itsentirety). The antibody can further be a binding-domain immunoglobulinfusion protein as described in U.S. Publication 20030118592, U.S.Publication 200330133939, and PCT Publication WO 02/056910, all toLedbetter et al., which are incorporated herein by reference in theirentireties.

5.5. Domain Antibodies

The anti-CD22 antibodies of the compositions and methods of theinvention can be domain antibodies, e.g., antibodies containing thesmall functional binding units of antibodies, corresponding to thevariable regions of the heavy (V_(H)) or light (V_(L)) chains of humanantibodies. Examples of domain antibodies include, but are not limitedto, those available from Domantis Limited (Cambridge, UK) and DomantisInc. (Cambridge, Mass., USA) that are specific to therapeutic targets(see, for example, WO04/058821; WO04/003019; U.S. Pat. Nos. 6,291,158;6,582,915; 6,696,245; and 6,593,081). Commercially available librariesof domain antibodies can be used to identify anti-CD22 domainantibodies. In certain embodiments, the anti-CD22 antibodies of theinvention comprise a CD22 functional binding unit and a Fc gammareceptor functional binding unit.

5.6. Diabodies

The term “diabodies” refers to small antibody fragments with twoantigen-binding sites, which fragments comprise a heavy chain variabledomain (V_(H)) connected to a light chain variable domain (V_(L)) in thesame polypeptide chain (V_(H)-V_(L)). By using a linker that is tooshort to allow pairing between the two domains on the same chain, thedomains are forced to pair with the complementary domains of anotherchain and create two antigen-binding sites. Diabodies are described morefully in, for example, EP 404,097; WO 93/11161; and Hollinger et al.,Proc. Natl. Acad. Sci. USA, 90:6444-6448 (1993).

5.7. Vaccibodies

In certain embodiments of the invention, the anti-CD22 antibodies areVaccibodies. Vaccibodies are dimeric polypeptides. Each monomer of avaccibody consists of a scFv with specificity for a surface molecule onAPC connected through a hinge region and a Cγ3 domain to a second scFv.In other embodiments of the invention, vaccibodies containing as one ofthe scFv's an anti-CD22 antibody fragment may be used to juxtapose thoseB cells to be destroyed and an effector cell that mediates ADCC. Forexample, see, Bogen et al., U.S. Patent Application Publication No.20040253238.

5.8. Linear Antibodies

In certain embodiments of the invention, the anti-CD22 antibodies arelinear antibodies. Linear antibodies comprise a pair of tandem Fdsegments (V_(H)-C_(H1)-V_(H)-C_(H1)) which form a pair ofantigen-binding regions. Linear antibodies can be bispecific ormonospecific. See, Zapata et al., Protein Eng., 8(10):1057-1062 (1995).

5.9. Parent Antibody

In certain embodiments of the invention, the anti-CD22 antibody is aparent antibody. A “parent antibody” is an antibody comprising an aminoacid sequence which lacks, or is deficient in, one or more amino acidresidues in or adjacent to one or more hypervariable regions thereofcompared to an altered/mutant antibody as herein disclosed. Thus, theparent antibody has a shorter hypervariable region than thecorresponding hypervariable region of an antibody mutant as hereindisclosed. The parent polypeptide may comprise a native sequence (i.e.,a naturally occurring) antibody (including a naturally occurring allelicvariant) or an antibody with pre-existing amino acid sequencemodifications (such as other insertions, deletions and/or substitutions)of a naturally occurring sequence. Preferably the parent antibody is ahumanized antibody or a human antibody.

5.10. Antibody Fragments

“Antibody fragments” comprise a portion of a full-length antibody,generally the antigen binding or variable region thereof. Examples ofantibody fragments include Fab, Fab′, F(ab′)₂, and Fv fragments;diabodies; linear antibodies; single-chain antibody molecules; andmultispecific antibodies formed from antibody fragments.

Traditionally, these fragments were derived via proteolytic digestion ofintact antibodies (see, e.g., Morimoto et al., Journal of Biochemicaland Biophysical Methods, 24:107-117 (1992) and Brennan et al., Science,229:81 (1985)). However, these fragments can now be produced directly byrecombinant host cells. For example, the antibody fragments can beisolated from the antibody phage libraries discussed above.Alternatively, Fab′-SH fragments can be directly recovered from E. coliand chemically coupled to form F(ab′)₂ fragments (Carter et al.,Bio/Technology, 10:163-167 (1992)). According to another approach,F(ab′)₂ fragments can be isolated directly from recombinant host cellculture. Other techniques for the production of antibody fragments willbe apparent to the skilled practitioner. In other embodiments, theantibody of choice is a single-chain Fv fragment (scFv). See, forexample, WO 93/16185. In certain embodiments, the antibody is not a Fabfragment.

5.11. Bispecific Antibodies

Bispecific antibodies are antibodies that have binding specificities forat least two different epitopes. Exemplary bispecific antibodies maybind to two different epitopes of the B cell surface marker. Other suchantibodies may bind a first B cell marker and further bind a second Bcell surface marker. Alternatively, an anti-B cell marker binding armmay be combined with an arm which binds to a triggering molecule on aleukocyte such as a T cell receptor molecule (e.g., CD2 or CD3), or Fcreceptors for IgG (FcγR), so as to focus cellular defense mechanisms tothe B cell. Bispecific antibodies may also be used to localize cytotoxicagents to the B cell. These antibodies possess a B cell marker-bindingarm and an arm which binds the cytotoxic agent (e.g., saporin,anti-interferon-α, vinca alkaloid, ricin A chain, methola-exate orradioactive isotope hapten). Bispecific antibodies can be prepared asfull-length antibodies or antibody fragments (e.g., F(ab′): bispecificantibodies).

Methods for making bispecific antibodies are known in the art. (See, forexample, Millstein et al., Nature, 305:537-539 (1983); Traunecker etal., EMBO J., 10:3655-3659 (1991); Suresh et al., Methods in Enzymology,121:210 (1986); Kostelny et al., J. Immunol., 148(5):1547-1553 (1992);Hollinger et al., Proc. Natl. Acad. Sci. USA, 90:6444-6448 (1993);Gruber et al., J. Immunol., 152:5368 (1994); U.S. Pat. Nos. 4,474,893;4,714,681; 4,925,648; 5,573,920; 5,601,81; 95,731,168; 4,676,980; and4,676,980, WO 94/04690; WO 91/00360; WO 92/200373; WO 93/17715; WO92/08802; and EP 03089.)

In one embodiment, where the anti-CD22 antibody of the compositions andmethods of the invention is bispecific, the anti-CD22 antibody is humanor humanized and has specificity for human CD22 and an epitope on a Tcell or is capable of binding to a human effector cell such as, forexample, a monocyte/macrophage and/or a natural killer cell to effectcell death.

5.12. Variant Fc Regions

The present invention provides formulation of proteins comprising avariant Fc region. That is, a non-naturally occurring Fc region, forexample an Fc region comprising one or more non-naturally occurringamino acid residues. Also encompassed by the variant Fc regions ofpresent invention are Fc regions which comprise amino acid deletions,additions and/or modifications.

It will be understood that Fc region as used herein includes thepolypeptides comprising the constant region of an antibody excluding thefirst constant region immunoglobulin domain. Thus Fc refers to the lasttwo constant region immunoglobulin domains of IgA, IgD, and IgG, and thelast three constant region immunoglobulin domains of IgE and IgM, andthe flexible hinge N-terminal to these domains. For IgA and IgM Fc mayinclude the J chain. For IgG, Fc comprises immunoglobulin domainsCgamma2 and Cgamma3 (Cγ2 and Cγ3) and the hinge between Cgamma1 (Cγ1)and Cgamma2 (Cγ2). Although the boundaries of the Fc region may vary,the human IgG heavy chain Fc region is usually defined to compriseresidues C226 or P230 to its carboxyl-terminus, wherein the numbering isaccording to the EU index as in Kabat et al. (1991, NIH Publication91-3242, National Technical Information Service, Springfield, Va.). The“EU index as set forth in Kabat” refers to the residue numbering of thehuman IgG1 EU antibody as described in Kabat et al. supra. Fc may referto this region in isolation, or this region in the context of anantibody, antibody fragment, or Fc fusion protein. An Fc variant proteinmay be an antibody, Fc fusion, or any protein or protein domain thatcomprises an Fc region. Particularly preferred are proteins comprisingvariant Fc regions, which are non-naturally occurring variants of an Fc.Note: Polymorphisms have been observed at a number of Fc positions,including but not limited to Kabat 270, 272, 312, 315, 356, and 358, andthus slight differences between the presented sequence and sequences inthe prior art may exist.

The present invention encompasses Fc variant proteins which have alteredbinding properties for an Fc ligand (e.g., an Fc receptor, C1q) relativeto a comparable molecule (e.g., a protein having the same amino acidsequence except having a wild type Fc region). Examples of bindingproperties include but are not limited to, binding specificity,equilibrium dissociation constant (KD), dissociation and associationrates (K_(off) and K_(on) respectively), binding affinity and/oravidity. It is generally understood that a binding molecule (e.g., a Fcvariant protein such as an antibody) with a low KD is preferable to abinding molecule with a high KD. However, in some instances the value ofthe kon or koff may be more relevant than the value of the KD. Oneskilled in the art can determine which kinetic parameter is mostimportant for a given antibody application.

The affinities and binding properties of an Fc domain for its ligand,may be determined by a variety of in vitro assay methods (biochemical orimmunological based assays) known in the art for determining Fc-FcγRinteractions, i.e., specific binding of an Fc region to an FcγRincluding but not limited to, equilibrium methods (e.g., enzyme-linkedimmunoabsorbent assay (ELISA), or radioimmunoassay (RIA)), or kinetics(e.g., BIACORE® analysis), and other methods such as indirect bindingassays, competitive inhibition assays, fluorescence resonance energytransfer (FRET), gel electrophoresis and chromatography (e.g., gelfiltration). These and other methods may utilize a label on one or moreof the components being examined and/or employ a variety of detectionmethods including but not limited to chromogenic, fluorescent,luminescent, or isotopic labels. A detailed description of bindingaffinities and kinetics can be found in Paul, W. E., ed., FundamentalImmunology, 4th Ed., Lippincott-Raven, Philadelphia (1999), whichfocuses on antibody-immunogen interactions.

In one embodiment, the Fc variant protein has enhanced binding to one ormore Fc ligand relative to a comparable molecule. In another embodiment,the Fc variant protein has an affinity for an Fc ligand that is at least2 fold, or at least 3 fold, or at least 5 fold, or at least 7 fold, or aleast 10 fold, or at least 20 fold, or at least 30 fold, or at least 40fold, or at least 50 fold, or at least 60 fold, or at least 70 fold, orat least 80 fold, or at least 90 fold, or at least 100 fold, or at least200 fold greater than that of a comparable molecule. In a specificembodiment, the Fc variant protein has enhanced binding to an Fcreceptor. In another specific embodiment, the Fc variant protein hasenhanced binding to the Fc receptor FcγRIIIA. In still another specificembodiment, the Fc variant protein has enhanced binding to the Fcreceptor FcRn. In yet another specific embodiment, the Fc variantprotein has enhanced binding to C1q relative to a comparable molecule.

The serum half-life of proteins comprising Fc regions may be increasedby increasing the binding affinity of the Fc region for FcRn. In oneembodiment, the Fc variant protein has enhanced serum half life relativeto comparable molecule.

“Antibody-dependent cell-mediated cytotoxicity” or “ADCC” refers to aform of cytotoxicity in which secreted Ig bound onto Fc receptors (FcRs)present on certain cytotoxic cells (e.g., Natural Killer (NK) cells,neutrophils, and macrophages) enables these cytotoxic effector cells tobind specifically to an antigen-bearing target cell and subsequentlykill the target cell with cytotoxins. Specific high-affinity IgGantibodies directed to the surface of target cells “arm” the cytotoxiccells and are absolutely required for such killing. Lysis of the targetcell is extracellular, requires direct cell-to-cell contact, and doesnot involve complement. It is contemplated that, in addition toantibodies, other proteins comprising Fc regions, specifically Fc fusionproteins, having the capacity to bind specifically to an antigen-bearingtarget cell will be able to effect cell-mediated cytotoxicity. Forsimplicity, the cell-mediated cytotoxicity resulting from the activityof an Fc fusion protein is also referred to herein as ADCC activity.

The ability of any particular Fc variant protein to mediate lysis of thetarget cell by ADCC can be assayed. To assess ADCC activity an Fcvariant protein of interest is added to target cells in combination withimmune effector cells, which may be activated by the antigen antibodycomplexes resulting in cytolysis of the target cell. Cytolysis isgenerally detected by the release of label (e.g. radioactive substrates,fluorescent dyes or natural intracellular proteins) from the lysedcells. Useful effector cells for such assays include peripheral bloodmononuclear cells (PBMC) and Natural Killer (NK) cells. Specificexamples of in vitro ADCC assays are described in Wisecarver et al.,1985 79:277-282; Bruggemann et al., 1987, J Exp. Med. 166:1351-1361;Wilkinson et al., 2001, J Immunol. Methods 258:183-191; Patel et al.,1995 J Immunol. Methods 184:29-38. Alternatively, or additionally, ADCCactivity of the Fc variant protein of interest may be assessed in vivo,e.g., in a animal model such as that disclosed in Clynes et al., 1998,Proc. Natl. Acad. Sci. USA 95:652-656.

In one embodiment, an Fc variant protein has enhanced ADCC activityrelative to a comparable molecule. In a specific embodiment, an Fcvariant protein has ADCC activity that is about at least 1.5 fold, or atleast 2 fold, or at least 3 fold, or at least 4 fold, or at least 5fold, or at least 10 fold, or at least 15 fold, or at least 20 fold, orat least 25 fold, or at least 30 fold, or at least 35 fold, or at least40 fold, or at least 45 fold, or at least 50 fold or at least 100 foldgreater than that of a comparable molecule. In another specificembodiment, an Fc variant protein has enhanced binding to the Fcreceptor FcγRIIIA and has enhanced ADCC activity relative to acomparable molecule. In other embodiments, the Fc variant protein hasboth enhanced ADCC activity and enhanced serum half life relative to acomparable molecule.

“Complement dependent cytotoxicity” and “CDC” refer to the lysing of atarget cell in the presence of complement. The complement activationpathway is initiated by the binding of the first component of thecomplement system (C1q) to a molecule, an antibody for example,complexed with a cognate antigen. To assess complement activation, a CDCassay, e.g. as described in Gazzano-Santoro et al., 1996, J. Immunol.Methods, 202:163, may be performed. In one embodiment, an Fc variantprotein has enhanced CDC activity relative to a comparable molecule. Ina specific embodiment, an Fc variant protein has CDC activity that is atleast 2 fold, or at least 3 fold, or at least 5 fold or at least 10 foldor at least 50 fold or at least 100 fold greater than that of acomparable molecule. In other embodiments, the Fc variant protein hasboth enhanced CDC activity and enhanced serum half life relative to acomparable molecule.

In one embodiment, the present invention provides formulations, whereinthe Fc region comprises a non-naturally occurring amino acid residue atone or more positions selected from the group consisting of 234, 235,236, 239, 240, 241, 243, 244, 245, 247, 252, 254, 256, 262, 263, 264,265, 266, 267, 269, 296, 297, 298, 299, 313, 325, 326, 327, 328, 329,330, 332, 333, and 334 as numbered by the EU index as set forth inKabat. Optionally, the Fc region may comprise a non-naturally occurringamino acid residue at additional and/or alternative positions known toone skilled in the art (see, e.g., U.S. Pat. Nos. 5,624,821; 6,277,375;6,737,056; PCT Patent Publications WO 01/58957; WO 02/06919; WO04/016750; WO 04/029207; WO 04/035752 and WO 05/040217).

In a specific embodiment, the present invention provides an Fc variantprotein formulation, wherein the Fc region comprises at least onenon-naturally occurring amino acid residue selected from the groupconsisting of 234D, 234E, 234N, 234Q, 234T, 234H, 234Y, 2341, 234V,234F, 235A, 235D, 235R, 235W, 235P, 235S, 235N, 235Q, 235T, 235H, 235Y,235I, 235V, 235F, 236E, 239D, 239E, 239N, 239Q, 239F, 239T, 239H, 239Y,240I, 240A, 240T, 240M, 241W, 241 L, 241Y, 241E, 241 R. 243W, 243L 243Y,243R, 243Q, 244H, 245A, 247V, 247G, 252Y, 254T, 256E, 262I, 262A, 262T,262E, 263I, 263A, 263T, 263M, 264L, 264I, 264W, 264T, 264R, 264F, 264M,264Y, 264E, 265G, 265N, 265Q, 265Y, 265F, 265V, 265I, 265L, 265H, 265T,266I, 266A, 266T, 266M, 267Q, 267L, 269H, 269Y, 269F, 269R, 296E, 296Q,296D, 296N, 296S, 296T, 296L, 296I, 296H, 269G, 297S, 297D, 297E, 298H,298I, 298T, 298F, 299I, 299L, 299A, 299S, 299V, 299H, 299F, 299E, 313F,325Q, 325L, 325I, 325D, 325E, 325A, 325T, 325V, 325H, 327G, 327W, 327N,327L, 328S, 328M, 328D, 328E, 328N, 328Q, 328F, 328I, 328V, 328T, 328H,328A, 329F, 329H, 329Q, 330K, 330G, 330T, 330C, 330L, 330Y, 330V, 330I,330F, 330R, 330H, 332D, 332S, 332W, 332F, 332E, 332N, 332Q, 332T, 332H,332Y, and 332A as numbered by the EU index as set forth in Kabat.Optionally, the Fc region may comprise additional and/or alternativenon-naturally occurring amino acid residues known to one skilled in theart (see, e.g., U.S. Pat. Nos. 5,624,821; 6,277,375; 6,737,056; PCTPatent Publications WO 01/58957; WO 02/06919; WO 04/016750; WO04/029207; WO 04/035752 and WO 05/040217).

In another embodiment, the present invention provides an Fc variantprotein formulation, wherein the Fc region comprises at least anon-naturally occurring amino acid at one or more positions selectedfrom the group consisting of 239, 330 and 332, as numbered by the EUindex as set forth in Kabat. In a specific embodiment, the presentinvention provides an Fc variant protein formulation, wherein the Fcregion comprises at least one non-naturally occurring amino acidselected from the group consisting of 239D, 330L and 332E, as numberedby the EU index as set forth in Kabat. Optionally, the Fc region mayfurther comprise additional non-naturally occurring amino acid at one ormore positions selected from the group consisting of 252, 254, and 256,as numbered by the EU index as set forth in Kabat. In a specificembodiment, the present invention provides an Fc variant proteinformulation, wherein the Fc region comprises at least one non-naturallyoccurring amino acid selected from the group consisting of 239D, 330Land 332E, as numbered by the EU index as set forth in Kabat and at leastone non-naturally occurring amino acid at one or more positions areselected from the group consisting of 252Y, 254T and 256E, as numberedby the EU index as set forth in Kabat.

In one embodiment, the Fc variants of the present invention may becombined with other known Fc variants such as those disclosed in Ghetieet al., 1997, Nat. Biotech. 15:637-40; Duncan et al, 1988, Nature332:563-564; Lund et al., 1991, J. Immunol 147:2657-2662; Lund et al,1992, Mol Immunol 29:53-59; Alegre et al, 1994, Transplantation57:1537-1543; Hutchins et al., 1995, Proc Natl. Acad Sci USA92:11980-11984; Jefferis et al, 1995, Immunol Lett. 44:111-117; Lund etal., 1995, Faseb J 9:115-119; Jefferis et al, 1996, Immunol Lett54:101-104; Lund et al, 1996, J Immunol 157:4963-4969; Armour et al.,1999, Eur J Immunol 29:2613-2624; Idusogie et al, 2000, J Immunol164:4178-4184; Reddy et al, 2000, J Immunol 164:1925-1933; Xu et al.,2000, Cell Immunol 200:16-26; Idusogie et al, 2001, J Immunol166:2571-2575; Shields et al., 2001, J Biol Chem 276:6591-6604; Jefferiset al, 2002, Immunol Lett 82:57-65; Presta et al., 2002, Biochem SocTrans 30:487-490); U.S. Pat. Nos. 5,624,821; 5,885,573; 5,677,425;6,165,745; 6,277,375; 5,869,046; 6,121,022; 5,624,821; 5,648,260;6,528,624; 6,194,551; 6,737,056; 6,821,505; 6,277,375; U.S. PatentPublication Nos. 2004/0002587 and PCT Publications WO 94/29351; WO99/58572; WO 00/42072; WO 02/060919; WO 04/029207; WO 04/099249; WO04/063351. Also encompassed by the present invention are Fc regionswhich comprise deletions, additions and/or modifications. Still othermodifications/substitutions/additions/deletions of the Fc domain will bereadily apparent to one skilled in the art.

Methods for generating non-naturally occurring Fc regions are known inthe art. For example, amino acid substitutions and/or deletions can begenerated by mutagenesis methods, including, but not limited to,site-directed mutagenesis (Kunkel, Proc. Natl. Acad. Sci. USA 82:488-492(1985)), PCR mutagenesis (Higuchi, in “PCR Protocols: A Guide to Methodsand Applications”, Academic Press, San Diego, pp. 177-183 (1990)), andcassette mutagenesis (Wells et al., Gene 34:315-323 (1985)). Preferably,site-directed mutagenesis is performed by the overlap-extension PCRmethod (Higuchi, in “PCR Technology: Principles and Applications for DNAAmplification”, Stockton Press, New York, pp. 61-70 (1989)).Alternatively, the technique of overlap-extension PCR (Higuchi, ibid.)can be used to introduce any desired mutation(s) into a target sequence(the starting DNA). For example, the first round of PCR in theoverlap-extension method involves amplifying the target sequence with anoutside primer (primer 1) and an internal mutagenesis primer (primer 3),and separately with a second outside primer (primer 4) and an internalprimer (primer 2), yielding two PCR segments (segments A and B). Theinternal mutagenesis primer (primer 3) is designed to contain mismatchesto the target sequence specifying the desired mutation(s). In the secondround of PCR, the products of the first round of PCR (segments A and B)are amplified by PCR using the two outside primers (primers 1 and 4).The resulting full-length PCR segment (segment C) is digested withrestriction enzymes and the resulting restriction fragment is clonedinto an appropriate vector. As the first step of mutagenesis, thestarting DNA (e.g., encoding an Fc fusion protein, an antibody or simplyan Fc region), is operably cloned into a mutagenesis vector. The primersare designed to reflect the desired amino acid substitution. Othermethods useful for the generation of variant Fc regions are known in theart (see, e.g., U.S. Pat. Nos. 5,624,821; 5,885,573; 5,677,425;6,165,745; 6,277,375; 5,869,046; 6,121,022; 5,624,821; 5,648,260;6,528,624; 6,194,551; 6,737,056; 6,821,505; 6,277,375; U.S. PatentPublication Nos. 2004/0002587 and PCT Publications WO 94/29351; WO99/58572; WO 00/42072; WO 02/060919; WO 04/029207; WO 04/099249; WO04/063351).

In some embodiments, an Fc variant protein comprises one or moreengineered glycoforms, i.e., a carbohydrate composition that iscovalently attached to the molecule comprising an Fc region. Engineeredglycoforms may be useful for a variety of purposes, including but notlimited to enhancing or reducing effector function. Engineeredglycoforms may be generated by any method known to one skilled in theart, for example by using engineered or variant expression strains, byco-expression with one or more enzymes, for example DIN-acetylglucosaminyltransferase III (GnTI11), by expressing a moleculecomprising an Fc region in various organisms or cell lines from variousorganisms, or by modifying carbohydrate(s) after the molecule comprisingFc region has been expressed. Methods for generating engineeredglycoforms are known in the art, and include but are not limited tothose described in Umana et al, 1999, Nat. Biotechnol 17:176-180; Davieset al., 20017 Biotechnol Bioeng 74:288-294; Shields et al, 2002, J BiolChem 277:26733-26740; Shinkawa et al., 2003, J Biol Chem 278:3466-3473)U.S. Pat. No. 6,602,684; U.S. Ser. No. 10/277,370; U.S. Ser. No.10/113,929; PCT WO 00/61739A1; PCT WO 01/292246A1; PCT WO 02/311140A1;PCT WO 02/30954A1; Potillegent™ technology (Biowa, Inc. Princeton,N.J.); GlycoMAb™ glycosylation engineering technology (GLYCARTbiotechnology AG, Zurich, Switzerland). See, e.g., WO 00061739;EA01229125; US 20030115614; Okazaki et al., 2004, JMB, 336: 1239-49.

5.13. Glycosylation of Antibodies

In still another embodiment, the glycosylation of antibodies utilized inaccordance with the invention is modified. For example, an aglycoslatedantibody can be made (i.e., the antibody lacks glycosylation).Glycosylation can be altered to, for example, increase the affinity ofthe antibody for a target antigen. Such carbohydrate modifications canbe accomplished by, for example, altering one or more sites ofglycosylation within the antibody sequence. For example, one or moreamino acid substitutions can be made that result in elimination of oneor more variable region framework glycosylation sites to therebyeliminate glycosylation at that site. Such aglycosylation may increasethe affinity of the antibody for antigen. Such an approach is describedin further detail in U.S. Pat. Nos. 5,714,350 and 6,350,861.Alternatively, one or more amino acid substitutions can be made thatresult in elimination of a glycosylation site present in the Fc region(e.g., Asparagine 297 of IgG). Furthermore, a glycosylated antibodiesmay be produced in bacterial cells which lack the necessaryglycosylation machinery.

Additionally or alternatively, an antibody can be made that has analtered type of glycosylation, such as a hypofucosylated antibody havingreduced amounts of fucosyl residues or an antibody having increasedbisecting GlcNAc structures. Such altered glycosylation patterns havebeen demonstrated to increase the ADCC ability of antibodies. Suchcarbohydrate modifications can be accomplished by, for example,expressing the antibody in a host cell with altered glycosylationmachinery. Cells with altered glycosylation machinery have beendescribed in the art and can be used as host cells in which to expressrecombinant antibodies of the invention to thereby produce an antibodywith altered glycosylation. See, for example, Shields, R. L. et al.(2002) J. Biol. Chem. 277:26733-26740; Umana et al. (1999) Nat. Biotech.17:176-1, as well as, European Patent No: EP 1,176,195; PCT PublicationsWO 03/035835; WO 99/54342.

5.14. Engineering Effector Function

It may be desirable to modify the anti-CD22 antibody of the inventionwith respect to effector function, so as to enhance the effectiveness ofthe antibody in treating B cell malignancies, for example. For example,cysteine residue(s) may be introduced in the Fc region, thereby allowinginterchain disulfide bond formation in this region. The homodimericantibody thus generated may have improved internalization capabilityand/or increased complement-mediated cell killing and/orantibody-dependent cellular cytotoxicity (ADCC). See, Caron et al., JExp Med., 176:1191-1195 (1992) and Shopes, B., J. Immunol.,148:2918-2922 (1992). Homodimeric antibodies with enhanced anti-tumoractivity may also be prepared using heterobifunctional cross-linkers asdescribed in Wolff et al., Cancer Research, 53:2560-2565 (1993).Alternatively, an antibody can be engineered which has dual Fc regionsand may thereby have enhanced complement lysis and ADCC capabilities.See, Stevenson et al., Anti-Cancer Drug Design, 3:219-230 (1989).

Other methods of engineering Fc regions of antibodies so as to altereffector functions are known in the art (e.g., U.S. Patent PublicationNo. 20040185045 and PCT Publication No. WO 2004/016750, both to Koeniget al., which describe altering the Fc region to enhance the bindingaffinity for FcγRIIB as compared with the binding affinity for FCγRIIA;see, also, PCT Publication Nos. WO 99/58572 to Armour et al., WO99/51642 to Idusogie et al., and U.S. Pat. No. 6,395,272 to Deo et al.;the disclosures of which are incorporated herein in their entireties).Methods of modifying the Fc region to decrease binding affinity toFcγRIIB are also known in the art (e.g., U.S. Patent Publication No.20010036459 and PCT Publication No. WO 01/79299, both to Ravetch et al.,the disclosures of which are incorporated herein in their entireties).Modified antibodies having variant Fc regions with enhanced bindingaffinity for FcγRIIIA and/or FcγRIIA as compared with a wildtype Fcregion have also been described (e.g., PCT Publication Nos. WO2004/063351, to Stavenhagen et al., the disclosure of which isincorporated herein in its entirety).

In vitro assays known in the art can be used to determine whether theanti-CD22 antibodies used in the compositions and methods of theinvention are capable of mediating ADCC, such as those described herein.

5.15. Manufacture/Production of Anti-CD22 Antibodies

Once a desired anti-CD22 antibody is engineered, the anti-CD22 antibodycan be produced on a commercial scale using methods that are well-knownin the art for large scale manufacturing of antibodies. For example,this can be accomplished using recombinant expressing systems such as,but not limited to, those described below.

5.16. Recombinant Expression Systems

Recombinant expression of an antibody of the invention or variantthereof, generally requires construction of an expression vectorcontaining a polynucleotide that encodes the antibody. Once apolynucleotide encoding an antibody molecule or a heavy or light chainof an antibody, or portion thereof (preferably, but not necessarily,containing the heavy or light chain variable domain), of the inventionhas been obtained, the vector for the production of the antibodymolecule may be produced by recombinant DNA technology using techniqueswell-known in the art. See, e.g., U.S. Pat. No. 6,331,415, which isincorporated herein by reference in its entirety. Thus, methods forpreparing a protein by expressing a polynucleotide containing anantibody encoding nucleotide sequence are described herein. Methodswhich are well-known to those skilled in the art can be used toconstruct expression vectors containing antibody coding sequences andappropriate transcriptional and translational control signals. Thesemethods include, for example, in vitro recombinant DNA techniques,synthetic techniques, and in vivo genetic recombination. The invention,thus, provides replicable vectors comprising a nucleotide sequenceencoding an antibody molecule of the invention, a heavy or light chainof an antibody, a heavy or light chain variable domain of an antibody ora portion thereof, or a heavy or light chain CDR, operably linked to apromoter. Such vectors may include the nucleotide sequence encoding theconstant region of the antibody molecule (see, e.g., InternationalPublication Nos. WO 86/05807 and WO 89/01036; and U.S. Pat. No.5,122,464) and the variable domain of the antibody may be cloned intosuch a vector for expression of the entire heavy, the entire lightchain, or both the entire heavy and light chains.

In an alternate embodiment, the anti-CD22 antibodies of the compositionsand methods of the invention can be made using targeted homologousrecombination to produce all or portions of the anti-CD22 antibodies(see, U.S. Pat. Nos. 6,063,630, 6,187,305, and 6,692,737). In certainembodiments, the anti-CD22 antibodies of the compositions and methods ofthe invention can be made using random recombination techniques toproduce all or portions of the anti-CD22 antibodies (see, U.S. Pat. Nos.6,361,972, 6,524,818, 6,541,221, and 6,623,958). Anti-CD22 antibodiescan also be produced in cells expressing an antibody from a genomicsequence of the cell comprising a modified immunoglobulin locus usingCre-mediated site-specific homologous recombination (see, U.S. Pat. No.6,091,001). Where human or humanized antibody production is desired, thehost cell line may be derived from human or nonhuman species includingmouse, and Chinese hampster. should be a human cell line. These methodsmay advantageously be used to engineer stable cell lines whichpermanently express the antibody molecule.

Once the expression vector is transferred to a host cell by conventionaltechniques, the transfected cells are then cultured by conventionaltechniques to produce an antibody of the invention. Thus, the inventionincludes host cells containing a polynucleotide encoding an antibody ofthe invention or fragments thereof, or a heavy or light chain thereof,or portion thereof, or a single-chain antibody of the invention,operably linked to a heterologous promoter. In certain embodiments forthe expression of double-chained antibodies, vectors encoding both theheavy and light chains may be co-expressed in the host cell forexpression of the entire immunoglobulin molecule, as detailed below.

A variety of host-expression vector systems may be utilized to expressthe anti-CD22 antibodies of the invention or portions thereof that canbe used in the engineering and generation of anti-CD22 antibodies (see,e.g., U.S. Pat. No. 5,807,715). For example, mammalian cells such asChinese hamster ovary cells (CHO), in conjunction with a vector such asthe major intermediate early gene promoter element from humancytomegalovirus is an effective expression system for antibodies(Foecking et al., Gene, 45:101 (1986); and Cockett et al.,Bio/Technology, 8:2 (1990)). In addition, a host cell strain may bechosen which modulates the expression of inserted antibody sequences, ormodifies and processes the antibody gene product in the specific fashiondesired. Such modifications (e.g., glycosylation) and processing (e.g.,cleavage) of protein products may be important for the function of theprotein. Different host cells have characteristic and specificmechanisms for the post-translational processing and modification ofproteins and gene products. Appropriate cell lines or host systems canbe chosen to ensure the correct modification and processing of theantibody or portion thereof expressed. To this end, eukaryotic hostcells which possess the cellular machinery for proper processing of theprimary transcript, glycosylation, and phosphorylation of the geneproduct may be used. Such mammalian host cells include but are notlimited to CHO, VERY, BHK, Hela, COS, MDCK, 293, 3T3, WI 38, BT483,Hs578T, HTB2, BT20 and T47D, NS0 (a murine myeloma cell line that doesnot endogenously produce any functional immunoglobulin chains), CRL7O3Oand HsS78Bst cells.

In one embodiment, human cell lines developed by immortalizing humanlymphocytes can be used to recombinantly produce monoclonal humananti-CD22 antibodies. In one embodiment, the human cell line PER.C6.(Crucell, Netherlands) can be used to recombinantly produce monoclonalhuman anti-CD22 antibodies.

In bacterial systems, a number of expression vectors may beadvantageously selected depending upon the use intended for the antibodymolecule being expressed. For example, when a large quantity of such anantibody is to be produced, for the generation of pharmaceuticalcompositions comprising an anti-CD22 antibody, vectors which direct theexpression of high levels of fusion protein products that are readilypurified may be desirable. Such vectors include, but are not limited to,the E. coli expression vector pUR278 (Ruther et al., EMBO, 12:1791(1983)), in which the antibody coding sequence may be ligatedindividually into the vector in frame with the lac Z coding region sothat a fusion protein is produced; pIN vectors (Inouye & Inouye, 1985,Nucleic Acids Res. 13:3101-3109 (1985); Van Heeke & Schuster, 1989, J.Biol. Chem., 24:5503-5509 (1989)); and the like. pGEX vectors may alsobe used to express foreign polypeptides as fusion proteins withglutathione 5-transferase (GST). In general, such fusion proteins aresoluble and can easily be purified from lysed cells by adsorption andbinding to matrix glutathione agarose beads followed by elution in thepresence of free glutathione. The pGEX vectors are designed to includethrombin or factor Xa protease cleavage sites so that the cloned targetgene product can be released from the GST moiety.

In an insect system, Autographa californica nuclear polyhedrosis virus(AcNPV) is used as a vector to express foreign genes. The virus grows inSpodoptera frugiperda cells. The antibody coding sequence may be clonedindividually into non-essential regions (for example, the polyhedringene) of the virus and placed under control of an AcNPV promoter (forexample, the polyhedrin promoter).

In mammalian host cells, a number of viral-based expression systems maybe utilized. In cases where an adenovirus is used as an expressionvector, the antibody coding sequence of interest may be ligated to anadenovirus transcription/translation control complex, e.g., the latepromoter and tripartite leader sequence. This chimeric gene may then beinserted in the adenovirus genome by in vitro or in vivo recombination.Insertion in a non-essential region of the viral genome (e.g., region E1or E3) will result in a recombinant virus that is viable and capable ofexpressing the antibody molecule in infected hosts (e.g., see, Logan &Shenk, Proc. Natl. Acad. Sci. USA, 81:355-359 (1984)). Specificinitiation signals may also be required for efficient translation ofinserted antibody coding sequences. These signals include the ATGinitiation codon and adjacent sequences. Furthermore, the initiationcodon should generally be in phase with the reading frame of the desiredcoding sequence to ensure translation of the entire insert. Theseexogenous translational control signals and initiation codons can be ofa variety of origins, both natural and synthetic. The efficiency ofexpression may be enhanced by the inclusion of appropriate transcriptionenhancer elements, transcription terminators, etc. (see, e.g., Bittneret al., Methods in Enzymol., 153:51-544(1987)).

Stable expression can be used for long-term, high-yield production ofrecombinant proteins. For example, cell lines which stably express theantibody molecule may be engineered. Rather than transient expressionsystems that use replicating expression vectors which contain viralorigins of replication, host cells can be transformed with DNAcontrolled by appropriate expression control elements (e.g., promoter,enhancer, sequences, transcription terminators, polyadenylation sites,etc.), and a selectable marker. Following the introduction of theforeign DNA, engineered cells may be allowed to grow for 1-2 days in anenriched media, and then are switched to a selective media. Theselectable marker in the recombinant plasmid confers resistance to theselection and allows cells to stably integrate the plasmid into theirchromosomes and grow to form foci which in turn can be cloned andexpanded into cell lines. Plasmids that encode the anti-CD22 antibodycan be used to introduce the gene/cDNA into any cell line suitable forproduction in culture. Alternatively, plasmids called “targetingvectors” can be used to introduce expression control elements (e.g.,promoters, enhancers, etc.) into appropriate chromosomal locations inthe host cell to “activate” the endogenous gene for anti-CD22antibodies.

A number of selection systems may be used, including, but not limitedto, the herpes simplex virus thymidine kinase (Wigler et al., Cell,11:223 (1977)), hypoxanthineguanine phosphoribosyltransferase (Szybalska& Szybalski, Proc. Natl. Acad. Sci. USA, 48:202 (1992)), and adeninephosphoribosyltransferase (Lowy et al., Cell, 22:8-17 (1980)) genes canbe employed in tk⁻, hgprt⁻ or aprT⁻ cells, respectively. Also,antimetabolite resistance can be used as the basis of selection for thefollowing genes: dhfr, which confers resistance to methotrexate (Wigleret al., Natl. Acad. Sci. USA, 77:357 (1980); O'Hare et al., Proc. Natl.Acad. Sci. USA, 78:1527 (1981)); gpt, which confers resistance tomycophenolic acid (Mulligan & Berg, Proc. Natl. Acad. Sci. USA, 78:2072(1981)); neo, which confers resistance to the aminoglycoside G-418 (Wuand Wu, Biotherapy 3:87-95 (1991); Tolstoshev, Ann. Rev. Pharmacol.Toxicol. 32:573-596 (1993); Mulligan, Science 260:926-932 (1993); andMorgan and Anderson, Ann. Rev. Biochem. 62:191-217 (1993); May, TIB TECH11(5):155-2 15 (1993)); and hygro, which confers resistance tohygromycin (Santerre et al., Gene, 30:147 (1984)). Methods commonlyknown in the art of recombinant DNA technology may be routinely appliedto select the desired recombinant clone, and such methods are described,for example, in Ausubel et al. (eds.), Current Protocols in MolecularBiology, John Wiley & Sons, NY (1993); Kriegler, Gene Transfer andExpression, A Laboratory Manual, Stockton Press, NY (1990); and inChapters 12 and 13, Dracopoli et al. (eds.), Current Protocols in HumanGenetics, John Wiley & Sons, NY (1994); Colberre-Garapin et al., 1981,J. Mol. Biol., 150:1, which are incorporated by reference herein intheir entireties.

The expression levels of an antibody molecule can be increased by vectoramplification (for a review, see, Bebbington and Hentschel, The use ofvectors based on gene amplification for the expression of cloned genesin mammalian cells in DNA cloning, Vol. 3. Academic Press, New York(1987)). When a marker in the vector system expressing antibody isamplifiable, increase in the level of inhibitor present in culture ofhost cell will increase the number of copies of the marker gene. Sincethe amplified region is associated with the antibody gene, production ofthe antibody will also increase (Crouse et al., Mol. Cell. Biol., 3:257(1983)). Antibody expression levels may be amplified through the userecombinant methods and tools known to those skilled in the art ofrecombinant protein production, including technologies that remodelsurrounding chromatin and enhance transgene expression in the form of anactive artificial transcriptional domain.

The host cell may be co-transfected with two expression vectors of theinvention, the first vector encoding a heavy chain derived polypeptideand the second vector encoding a light chain derived polypeptide. Thetwo vectors may contain identical selectable markers which enable equalexpression of heavy and light chain polypeptides. Alternatively, asingle vector may be used which encodes, and is capable of expressing,both heavy and light chain polypeptides. In such situations, the lightchain should be placed before the heavy chain to avoid an excess oftoxic free heavy chain (Proudfoot, Nature 322:562-65 (1986); and Kohler,1980, Proc. Natl. Acad. Sci. USA, 77:2197 (1980)). The coding sequencesfor the heavy and light chains may comprise cDNA or genomic DNA.

Once an antibody molecule of the invention has been produced byrecombinant expression, it may be purified by any method known in theart for purification of an immunoglobulin molecule, for example, bychromatography (e.g., ion exchange, affinity, particularly by affinityfor the specific antigen after Protein A, and sizing columnchromatography), centrifugation, differential solubility, or by anyother standard technique for the purification of proteins. Further, theantibodies of the present invention or fragments thereof may be fused toheterologous polypeptide sequences described herein or otherwise knownin the art to facilitate purification.

5.16.1. Antibody Purification and Isolation

When using recombinant techniques, the antibody can be producedintracellularly, in the periplasmic space, or directly secreted into themedium. If the antibody is produced intracellularly, as a first step,the particulate debris, either host cells or lysed fragments, isremoved, for example, by centrifugation or ultrafiltration. Carter etal., Bio/Technology, 10:163-167 (1992) describe a procedure forisolating antibodies which are secreted into the periplasmic space of E.coli. Briefly, cell paste is thawed in the presence of sodium acetate(pH 3.5), EDTA, and phenylmethylsulfonylfluoride (PMSF) over about 30min. Cell debris can be removed by centrifugation. Where the antibodymutant is secreted into the medium, supernatants from such expressionsystems are generally first concentrated using a commercially availableprotein concentration filter, for example, an Amicon or MilliporePellicon ultrafiltration unit. A protease inhibitor such as PMSF may beincluded in any of the foregoing steps to inhibit proteolysis andantibiotics may be included to prevent the growth of adventitiouscontaminants.

The antibody composition prepared from the cells can be purified using,for example, hydroxylapatite chromatography, hydrophobic interactionchromatography, ion exchange chromatography, gel electrophoresis,dialysis, and/or affinity chromatography either alone or in combinationwith other purification steps. The suitability of protein A as anaffinity ligand depends on the species and isotype of any immunoglobulinFc domain that is present in the antibody mutant. Protein A can be usedto purify antibodies that are based on human γ1., γ 2, or γ 4 heavychains (Lindmark et al., J. Immunol. Methods, 62:1-13 (1983)). Protein Gis recommended for all mouse isotypes and for human γ3 (Guss et al.,EMBO J, 5:15671575 (1986)). The matrix to which the affinity ligand isattached is most often agarose, but other matrices are available.Mechanically stable matrices such as controlled pore glass orpoly(styrenedivinyl)benzene allow for faster flow rates and shorterprocessing times than can be achieved with agarose. Where the antibodycomprises a CH₃ domain, the Bakerbond ABX resin (J. T. Baker,Phillipsburg, N.J.) is useful for purification. Other techniques forprotein purification such as fractionation on an ion-exchange column,ethanol precipitation, Reverse Phase HPLC, chromatography on silica,chromatography on heparin, SEPHAROSE chromatography on an anion orcation exchange resin (such as a polyaspartic acid column),chromatofocusing, SDS-PAGE, and ammonium sulfate precipitation are alsoavailable depending on the antibody to be recovered.

Following any preliminary purification step(s), the mixture comprisingthe antibody of interest and contaminants may be subjected to low pHhydrophobic interaction chromatography using an elution buffer at a pHbetween about 2.5-4.5, preferably performed at low salt concentrations(e.g., from about 0-0.25 M salt).

5.17. Therapeutic Anti-CD22 Antibodies

The anti-CD22 antibody used in the compositions and methods of theinvention is preferably a human antibody or a humanized antibody thatpreferably mediates B lineage cell apoptosis and/or human ADCC, or isselected from known anti-CD22 antibodies that preferably mediate Blineage cell apoptosis and/or human ADCC. In certain embodiments, theanti-CD22 antibodies can be chimeric antibodies. In certain embodiments,anti-CD22 antibody is a monoclonal human, humanized, or chimericanti-CD22 antibody. The anti-CD22 antibody used in the compositions andmethods of the invention is preferably a human antibody or a humanizedantibody of the IgG1 or IgG3 human isotype or any IgG1 or IgG3 allelefound in the human population. In other embodiments, the anti-CD22antibody used in the compositions and methods of the invention ispreferably a human antibody or a humanized antibody of the IgG2 or IgG4human isotype or any IgG2 or IgG4 allele found in the human population.

While such antibodies can be generated using the techniques describedabove, in other embodiments of the invention, the murine antibodiesHB22.7 as described herein or other commercially available anti-CD22antibodies can be chimerized, humanized, or made into human antibodies.

For example, known anti-CD22 antibodies that can be used include, butare not limited to, HB22.2, HB22.5, HB22.12, HB22.13, HB22.15, HB22.17,HB22.18, HB22.19, HB22.22, HB22.23, HB22.25, HB22.26, HB22.27, HB22.28,HB22.33, 196-9, (Engel et al. 1993. J. Immunol. 150:4719-4732 and Engelet al 1995. J. Exp. Med. 181:1581-1586), HD37 (IgG1) (DAKO, Carpinteria,Calif.), BU12 (G.D. Johnson, University of Birmingham, Birmingham,United Kingdom), 4G7 (IgG1) (Becton-Dickinson, Heidelberg, Germany),J4.119 (Beckman Coulter, Krefeld, Germany), B43 (PharMingen, San Diego,Calif.), SJ25C1 (BD PharMingen, San Diego, Calif.), FMC63 (IgG2a)(Chemicon Int'l., Temecula, Calif.) (Nicholson et al., Mol. Immunol.,34:1157-1165 (1997); Pietersz et al., Cancer Immunol. Immunotherapy,41:53-60 (1995); and Zola et al., Immunol. Cell Biol., 69:411-422(1991)), B4 (IgG1) (Beckman Coulter, Miami, Fla.) Nadler et al., J.Immunol., 131:244-250 (1983), and/or HD237 (IgG2b) (Fourth InternationalWorkshop on Human Leukocyte Differentiation Antigens, Vienna, Austria,1989; and Pezzutto et al., J. Immunol., 138:2793-2799 (1987)).

In certain embodiments, the anti-CD22 antibody of the inventioncomprises the VH domain sequence of the humanized VH designatedHB22.7RHOv2ACD, which comprises an amino acid sequence of SEQ ID NO:59.In other embodiments, the anti-CD22 antibody of the invention comprisesthe VH domain sequence of the humanized VH designated HB22.7RHF, whichcomprises the amino acid sequence of SEQ ID NO:25.

In certain embodiments, the anti-CD22 antibody of the invention comprisea heavy chain variable region, VH, comprising at least one CDR sequenceselected from DYGVN (SEQ ID NO: 62), IIWGDGRTDYNSALKS (SEQ ID NO: 63),or APGNRAMEY (SEQ ID NO: 64); and at least one FW region selected fromQVQLQESGPALVKPTQTLTLTCTFSGFSLS (SEQ ID NO:73),QVQLQESGPALVKPTQTLTLTCTVSGFSLS (SEQ ID NO:74), WIRQPPGKALEWLA (SEQ IDNO:75), WIRQPPGKALEWLG (SEQ ID NO:76), RLSISKDTSKNQVVLRMTNVDPVDTATYFCAR(SEQ ID NO:77), RLSISKDNSKNQVVLRMTNVDPVDTATYFCAR (SEQ ID NO:78), orWGQGTVVTVSS(SEQ ID NO:79).

In another embodiments, the anti-CD22 antibody of the invention comprisea heavy chain variable region, VH, comprising at least one CDR sequenceselected from DYGVN (SEQ ID NO: 62), IIWGDGRTDYNSALKS (SEQ ID NO: 63),or APGNRAMEY (SEQ ID NO: 64); and at least one FW region selected fromQVQLEESGGGVVRPGRSLRLSCAASGFTFD (SEQ ID NO:80),QVQLEESGGGVVRPGRSLRLSCAASGFTFS (SEQ ID NO:81),QVQLEESGGGVVRPGRSLRLSCAASGFTLD (SEQ ID NO:82),QVQLEESGGGVVRPGRSLRLSCAASGFTLS (SEQ ID NO:83), WIRQAPGKGLEWVT (SEQ IDNO:84), WIRQAPGKGLEWVG (SEQ ID NO:85), RFTVSRNNSNNTLSLQMNSLTTEDTAVYYCVR(SEQ ID NO:86), RLTVSRNNSNNTLSLQMNSLTTEDTAVYYCVR (SEQ ID NO:87), orWGQGVLVTVS (SEQ ID NO:88).

In another embodiments, the anti-CD22 antibody of the invention comprisea heavy chain variable region, VH, comprising at least one CDR sequenceselected from DYGVN (SEQ ID NO: 62), IIWGDGRTDYNSALKS (SEQ ID NO: 63),or APGNRAMEY (SEQ ID NO: 64); and at least one FW region selected fromEVQLVESGGGLVQPGGSLRLSCAASGFTFS (SEQ ID NO:96),EVQLVESGGGLVQPGGSLRLSCAASGFTLS (SEQ ID NO:128), WVRQAPGKGLEWIS (SEQ IDNO:97), WVRQAPGKGLEWIG (SEQ ID NO:129), RLIISRDNYKNTMSLQMYSLSAADTAIYFCVK(SEQ ID NO:89), RFNISRDNYKNTMSLQMYSLSAADTAIYFCVK (SEQ ID NO:90),RFIISRDNYKNTNSLQMYSLSAADTAIYFCVK (SEQ ID NO:91),RLNISRDNYKNTMSLQMYSLSAADTAIYFCVK (SEQ ID NO:92),RLIISRDNYKNTNSLQMYSLSAADTAIYFCVK (SEQ ID NO:93),RFNISRDNYKNTNSLQMYSLSAADTAIYFCVK (SEQ ID NO:94),RLNISRDNYKNTNSLQMYSLSAADTAIYFCVK (SEQ ID NO:95), or WGQGTMVTVS (SEQ IDNO:99).

In another embodiment, the anti-CD22 antibody of the invention comprisea heavy chain variable region, VH, comprising at least one CDR sequenceselected from DYGVN (SEQ ID NO: 62), IIWGDGRTDYNSALKS (SEQ ID NO: 63),or APGNRAMEY (SEQ ID NO: 64); and at least one FW region selected fromQVQLEESGGGVVRPGRSLRLSCAASGFTFD (SEQ ID NO:80),QVQLEESGGGVVRPGRSLRLSCAASGFTLD (SEQ ID NO:82),QVQLEESGGGVVRPGRSLRLSCAASGFTFS (SEQ ID NO:81),QVQLEESGGGVVRPGRSLRLSCAASGFTLS (SEQ ID NO:83), WIRQAPGKGLEWVT (SEQ IDNO:84), WIRQAPGKGLEWVG (SEQ ID NO:85), RFTISRNNSNNTLSLQMNSLTTEDTAVYYCVR(SEQ ID NO:100), RLTISRNNSNNTLSLQMNSLTTEDTAVYYCVR (SEQ ID NO:101), orWGQGVLVTVS (SEQ ID NO:88).

In another embodiments, the anti-CD22 antibody of the invention comprisea heavy chain variable region, VH, comprising at least one CDR sequenceselected from DYGVN (SEQ ID NO: 62), IIWGDGRTDYNSALKS (SEQ ID NO: 63),or APGNRAMEY (SEQ ID NO: 64); and at least one FW region selected fromQVQLEESGGGVVRPGRSLRLSCAASGFTFD (SEQ ID NO:80),QVQLEESGGGVVRPGRSLRLSCAASGFTLD (SEQ ID NO:82),QVQLEESGGGVVRPGRSLRLSCAASGFTFS (SEQ ID NO:81),QVQLEESGGGVVRPGRSLRLSCAASGFTLS (SEQ ID NO:83), WIRQAPGKGLEWVT (SEQ IDNO:84), WIRQAPGKGLEWVG (SEQ ID NO:85), RFTVSRNNSNNTLSLQMNSLTTEDTAVYYCVR(SEQ ID NO:86), RLTVSRNNSNNTLSLQMNSLTTEDTAVYYCVR (SEQ ID NO:87), orWGQGVLVTVS (SEQ ID NO:88).

In another embodiments, the anti-CD22 antibody of the invention comprisea heavy chain variable region, VH, comprising at least one CDR sequenceselected from DYGVN (SEQ ID NO: 62), IIWGDGRTDYNSALKS (SEQ ID NO: 63),or APGNRAMEY (SEQ ID NO: 64); and at least one FW region selected fromELQLVESGGGFVQPGGSLRLSCAASGFPFR (SEQ ID NO:102),ELQLVESGGGFVQPGGSLRLSCAASGFPLR (SEQ ID NO:103),ELQLVESGGGFVQPGGSLRLSCAASGFPFS (SEQ ID NO:104),ELQLVESGGGFVQPGGSLRLSCAASGFPLS (SEQ ID NO:105), WVRQGPGKGLVWVS (SEQ IDNO:116), RVTISRDNAKKMVYPQMNSLRAEDTAMYYCHC (SEQ ID NO:106),RVTISRDNAKKMVYPQMNSLRAEDTAMYYCHR (SEQ ID NO:107),RVTISRDNAKKMVYPQMNSLRAEDTAMYYCHK (SEQ ID NO:108),RVTISRDNAKKMVYPQMNSLRAEDTAMYYCVC (SEQ ID NO:109),RVTISRDNAKKMVYPQMNSLRAEDTAMYYCVR (SEQ ID NO:110),RVTISRDNAKKMVYPQMNSLRAEDTAMYYCVK (SEQ ID NO:111),RVTISRDNAKKMVYPQMNSLRAEDTAMYYCAC (SEQ ID NO:112),RVTISRDNAKKMVYPQMNSLRAEDTAMYYCAR (SEQ ID NO:113),RVTISRDNAKKMVYPQMNSLRAEDTAMYYCAK (SEQ ID NO:114), or WGQGTLVTV (SEQ IDNO:129).

In further embodiments, the anti-CD22 antibody of the invention comprisea light chain variable region, VK, comprising at least one CDR sequenceselected from KASQSVTNDVA (SEQ ID NO: 65), YASNRYT (SEQ ID NO: 66), orQQDYRSPWT (SEQ ID NO: 67); and at least one FW region selected fromDIVMTQSPSSLSASVGDRVTITC (SEQ ID NO:117), WYQQKPGKAPKLLIY (SEQ IDNO:118), GVPSRFSGSGSGTDFTLTISSLQPEDFATYYC (SEQ ID NO:119),GVPDRFSGSGSGTDFTLTISSLQPEDFATYYC (SEQ ID NO:120),GVPSRFSGSGYGTDFTLTISSLQPEDFATYYC (SEQ ID NO:121),GVPSRFSGSGSGTDFTLTISSLQPEDFATYFC (SEQ ID NO:122),GVPDRFSGSGYGTDFTLTISSLQPEDFATYYC (SEQ ID NO:123),GVPDRFSGSGSGTDFTLTISSLQPEDFATYFC (SEQ ID NO:124),GVPSRFSGSGYGTDFTLTISSLQPEDFATYFC (SEQ ID NO:125),GVPDRFSGSGYGTDFTLTISSLQPEDFATYFC (SEQ ID NO:126), or FGGGTKVEIKRT (SEQID NO:127).

In certain embodiments, the anti-CD22 antibody of the invention furthercomprises the VK domain sequence of the humanized VK designatedHB22.7RKC, which comprises an amino acid sequence of SEQ ID NO:39. Inother embodiments, the anti-CD22 antibody of the invention comprises theVK domain sequence of the humanized VK designated HB22.7RKA, whichcomprises an amino acid sequence of SEQ ID NO:35.

In certain embodiments, the antibody is an isotype switched variant of aknown antibody (e.g., to an IgG1 or IgG3 human isotype) such as thosedescribed above.

The anti-CD22 antibodies used in the compositions and methods of theinvention can be naked antibodies, immunoconjugates or fusion proteins.Preferably the anti-CD22 antibodies described above for use in thecompositions and methods of the invention are able to reduce or depleteB cells and circulating immunoglobulin in a human treated therewith.Depletion of B cells can be in circulating B cells, or in particulartissues such as, but not limited to, bone marrow, spleen, gut-associatedlymphoid tissues, and/or lymph nodes. Such depletion may be achieved viavarious mechanisms such as antibody-dependent cell-mediated cytotoxicity(ADCC), and/or by blocking of CD22 interaction with its intended ligand,and/or complement dependent cytotoxicity (CDC), inhibition of B cellproliferation and/or induction of B cell death (e.g., via apoptosis). By“depletion” of B cells it is meant a reduction in circulating B cellsand/or B cells in particular tissue(s) by at least about 10%, 15%, 20%,25%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, 90%,95% or more. In particular embodiments, virtually all detectable B cellsare depleted from the circulation and/or particular tissue(s). By“depletion” of circulating immunoglobulin (Ig) it is meant a reductionby at least about 25%, 40%, 50%, 65%, 75%, 80%, 85%, 90%, 95% or more.In particular embodiments, virtually all detectable Ig is depleted fromthe circulation.

5.17.1. Screening of Antibodies for Human CD22 Binding

Binding assays can be used to identify antibodies that bind the humanCD22 antigen. Binding assays may be performed either as direct bindingassays or as competition-binding assays. Binding can be detected usingstandard ELISA or standard Flow Cytometry assays. In a direct bindingassay, a candidate antibody is tested for binding to human CD22 antigen.In certain embodiments, the screening assays comprise, in a second step,determining the ability to cause cell death or apoptosis of B cellsexpressing human CD22. Competition-binding assays, on the other hand,assess the ability of a candidate antibody to compete with a knownanti-CD22 antibody or other compound that binds human CD22.

In a direct binding assay, the human CD22 antigen is contacted with acandidate antibody under conditions that allow binding of the candidateantibody to the human CD22 antigen. The binding may take place insolution or on a solid surface. Preferably, the candidate antibody ispreviously labeled for detection. Any detectable compound may be usedfor labeling, such as but not limited to, a luminescent, fluorescent, orradioactive isotope or group containing same, or a nonisotopic label,such as an enzyme or dye. After a period of incubation sufficient forbinding to take place, the reaction is exposed to conditions andmanipulations that remove excess or non-specifically bound antibody.Typically, it involves washing with an appropriate buffer. Finally, thepresence of a CD22-antibody complex is detected.

In a competition-binding assay, a candidate antibody is evaluated forits ability to inhibit or displace the binding of a known anti-CD22antibody (or other compound) to the human CD22 antigen. A labeled knownbinder of CD22 may be mixed with the candidate antibody, and placedunder conditions in which the interaction between them would normallyoccur, with and without the addition of the candidate antibody. Theamount of labeled known binder of CD22 that binds the human CD22 may becompared to the amount bound in the presence or absence of the candidateantibody.

In one embodiment, the binding assay is carried out with one or morecomponents immobilized on a solid surface to facilitate antibody antigencomplex formation and detection. In various embodiments, the solidsupport could be, but is not restricted to, polycarbonate, polystyrene,polypropylene, polyethylene, glass, nitrocellulose, dextran, nylon,polyacrylamide and agarose. The support configuration can include beads,membranes, microparticles, the interior surface of a reaction vesselsuch as a microtiter plate, test tube or other reaction vessel. Theimmobilization of human CD22, or other component, can be achievedthrough covalent or non-covalent attachments. In one embodiment, theattachment may be indirect, i.e., through an attached antibody. Inanother embodiment, the human CD22 antigen and negative controls aretagged with an epitope, such as glutathione S-transferase (GST) so thatthe attachment to the solid surface can be mediated by a commerciallyavailable antibody such as anti-GST (Santa Cruz Biotechnology).

For example, such an affinity binding assay may be performed using thehuman CD22 antigen which is immobilized to a solid support. Typically,the non-mobilized component of the binding reaction, in this case thecandidate anti-CD22 antibody, is labeled to enable detection. A varietyof labeling methods are available and may be used, such as luminescent,chromophore, fluorescent, or radioactive isotope or group containingsame, and nonisotopic labels, such as enzymes or dyes. In oneembodiment, the candidate anti-CD22 antibody is labeled with afluorophore such as fluorescein isothiocyanate (FITC, available fromSigma Chemicals, St. Louis). Such an affinity binding assay may beperformed using the human CD22 antigen immobilized on a solid surface.Anti-CD22 antibodies are then incubated with the antigen and thespecific binding of antibodies is detected by methods known in the artincluding, but not limited to, BiaCore Analyses, ELISA, FMET and RIAmethods.

Finally, the label remaining on the solid surface may be detected by anydetection method known in the art. For example, if the candidateanti-CD22 antibody is labeled with a fluorophore, a fluorimeter may beused to detect complexes.

Preferably, the human CD22 antigen is added to binding assays in theform of intact cells that express human CD22 antigen, or isolatedmembranes containing human CD22 antigen. Thus, direct binding to humanCD22 antigen may be assayed in intact cells in culture or in animalmodels in the presence and absence of the candidate anti-CD22 antibody.A labeled candidate anti-CD22 antibody may be mixed with cells thatexpress human CD22 antigen, or with crude extracts obtained from suchcells, and the candidate anti-CD22 antibody may be added. Isolatedmembranes may be used to identify candidate anti-CD22 antibodies thatinteract with human CD22. For example, in a typical experiment usingisolated membranes, cells may be genetically engineered to express humanCD22 antigen. Membranes can be harvested by standard techniques and usedin an in vitro binding assay. Labeled candidate anti-CD22 antibody(e.g., fluorescent labeled antibody) is bound to the membranes andassayed for specific activity; specific binding is determined bycomparison with binding assays performed in the presence of excessunlabeled (cold) candidate anti-CD22 antibody. Alternatively, solublehuman CD22 antigen may be recombinantly expressed and utilized innon-cell based assays to identify antibodies that bind to human CD22antigen. The recombinantly expressed human CD22 polypeptides can be usedin the non-cell based screening assays. Alternatively, peptidescorresponding to one or more of the binding portions of human CD22antigen, or fusion proteins containing one or more of the bindingportions of human CD22 antigen can be used in non-cell based assaysystems to identify antibodies that bind to portions of human CD22antigen. In non-cell based assays the recombinantly expressed human CD22is attached to a solid substrate such as a test tube, microtiter well ora column, by means well-known to those in the art (see, Ausubel et al.,supra). The test antibodies are then assayed for their ability to bindto human CD22 antigen.

Alternatively, the binding reaction may be carried out in solution. Inthis assay, the labeled component is allowed to interact with itsbinding partner(s) in solution. If the size differences between thelabeled component and its binding partner(s) permit such a separation,the separation can be achieved by passing the products of the bindingreaction through an ultrafilter whose pores allow passage of unboundlabeled component but not of its binding partner(s) or of labeledcomponent bound to its partner(s). Separation can also be achieved usingany reagent capable of capturing a binding partner of the labeledcomponent from solution, such as an antibody against the binding partnerand so on.

In one embodiment, for example, a phage library can be screened bypassing phage from a continuous phage display library through a columncontaining purified human CD22 antigen, or derivative, analog, fragment,or domain, thereof, linked to a solid phase, such as plastic beads. Byaltering the stringency of the washing buffer, it is possible to enrichfor phage that express peptides with high affinity for human CD22antigen. Phage isolated from the column can be cloned and affinities canbe measured directly. Knowing which antibodies and their amino acidsequences confer the strongest binding to human CD22 antigen, computermodels can be used to identify the molecular contacts between CD22antigen and the candidate antibody.

In another specific embodiment of this aspect of the invention, thesolid support is membrane containing human CD22 antigen attached to amicrotiter dish. Candidate antibodies, for example, can bind cells thatexpress library antibodies cultivated under conditions that allowexpression of the library members in the microtiter dish. Librarymembers that bind to the human CD22 are harvested. Such methods, aregenerally described by way of example in Parmley and Smith, 1988, Gene,73:305-318; Fowlkes et al., 1992, BioTechniques, 13:422-427; PCTPublication No. WO94/18318; and in references cited hereinabove.Antibodies identified as binding to human CD22 antigen can be of any ofthe types or modifications of antibodies described above.

5.17.2. Screening of Antibodies for Human ADCC Effector Function

Antibodies of the human IgG class, which have functional characteristicssuch a long half-life in serum and the ability to mediate variouseffector functions are used in certain embodiments of the invention(Monoclonal Antibodies: Principles and Applications, Wiley-Liss, Inc.,Chapter 1 (1995)). The human IgG class antibody is further classifiedinto the following 4 subclasses: IgG1, IgG2, IgG3 and IgG4. A largenumber of studies have so far been conducted for ADCC and CDC aseffector functions of the IgG class antibody, and it has been reportedthat among antibodies of the human IgG class, the IgG1 subclass has thehighest ADCC activity and CDC activity in humans (Chemical Immunology,65, 88 (1997)).

Expression of ADCC activity and CDC activity of the human IgG1 subclassantibodies generally involves binding of the Fc region of the antibodyto a receptor for an antibody (hereinafter referred to as “FcγR”)existing on the surface of effector cells such as killer cells, naturalkiller cells or activated macrophages. Various complement components canbe bound. Regarding the binding, it has been suggested that severalamino acid residues in the hinge region and the second domain of Cregion (hereinafter referred to as “Cγ2 domain”) of the antibody areimportant (Eur. J. Immunol., 23, 1098 (1993), Immunology, 86, 319(1995), Chemical Immunology, 65, 88 (1997)) and that a sugar chain inthe Cγ2 domain (Chemical Immunology, 65, 88 (1997)) is also important.

The anti-CD22 antibodies of the invention can be modified with respectto effector function, e.g., so as to enhance ADCC and/or complementdependent cytotoxicity (CDC) of the antibody. This may be achieved byintroducing one or more amino acid substitutions in the Fc region of anantibody. Alternatively or additionally, cysteine residue(s) may beintroduced in the Fc region, allowing for interchain disulfide bondformation in this region. In this way a homodimeric antibody can begenerated that may have improved internalization capability and orincreased complement-mediated cell killing and ADCC (Caron et al., J.Exp. Med., 176:1191-1195 (1992) and Shopes, J. Immunol., 148:2918-2922(1992)). Heterobifunctional cross-linkers can also be used to generatehomodimeric antibodies with enhanced anti-tumor activity (Wolff et al.,Cancer Research, 53:2560-2565 (1993)). Antibodies can also be engineeredto have two or more Fc regions resulting in enhanced complement lysisand ADCC capabilities (Stevenson et al., Anti-Cancer Drug Design,(3)219-230 (1989)).

Other methods of engineering Fc regions of antibodies so as to altereffector functions are known in the art (e.g., U.S. Patent PublicationNo. 20040185045 and PCT Publication No. WO 2004/016750, both to Koeniget al., which describe altering the Fc region to enhance the bindingaffinity for FcγRIIB as compared with the binding affinity for FCγRIIA;see also PCT Publication Nos. WO 99/58572 to Armour et al., WO 99/51642to Idusogie et al., and U.S. Pat. No. 6,395,272 to Deo et al.; thedisclosures of which are incorporated herein in their entireties).Methods of modifying the Fc region to decrease binding affinity toFcγRIIB are also known in the art (e.g., U.S. Patent Publication No.20010036459 and PCT Publication No. WO 01/79299, both to Ravetch et al.,the disclosures of which are incorporated herein in their entireties).Modified antibodies having variant Fc regions with enhanced bindingaffinity for FcγRIIIA and/or FcγRIIA as compared with a wildtype Fcregion have also been described (e.g., PCT Publication No. WO2004/063351, to Stavenhagen et al.; the disclosure of which isincorporated herein in its entirety).

At least four different types of FcγR have been found, which arerespectively called FcγRI (CD64), FcγRII (CD32), FcγRIII (CD16), andFcγRIV. In human, FcγRII and FcγRIII are further classified into FcγRIIaand FcγRIIb, and FcγRIIIa and FcγRIIIb, respectively. FcγR is a membraneprotein belonging to the immunoglobulin superfamily, FcγRII, FcγRIII,and FcγRIV have an α chain having an extracellular region containing twoimmunoglobulin-like domains, FcγRI has an α chain having anextracellular region containing three immunoglobulin-like domains, as aconstituting component, and the α chain is involved in the IgG bindingactivity. In addition, FcγRI and FcγRIII have a γ chain or ζ chain as aconstituting component which has a signal transduction function inassociation with the α chain (Annu. Rev. Immunol., 18, 709 (2000), Annu.Rev. Immunol., 19, 275 (2001)). FcγRIV has been described by Bruhns etal., Clin. Invest. Med., (Canada) 27:3 D (2004).

To assess ADCC activity of an anti-CD22 antibody of interest, an invitro ADCC assay can be used, such as that described in U.S. Pat. No.5,500,362 or 5,821,337. Useful effector cells for such assays includeperipheral blood mononuclear cells (PBMC) and Natural Killer (NK) cells.For example, the ability of any particular antibody to mediate lysis ofthe target cell by complement activation and/or ADCC can be assayed. Thecells of interest are grown and labeled in vitro; the antibody is addedto the cell culture in combination with immune cells which may beactivated by the antigen-antibody complexes; i.e., effector cellsinvolved in the ADCC response. The antibody can also be tested forcomplement activation. In either case, cytolysis of the target cells isdetected by the release of label from the lysed cells. In fact,antibodies can be screened using the patient's own serum as a source ofcomplement and/or immune cells. The antibodies that are capable ofmediating human ADCC in the in vitro test can then be usedtherapeutically in that particular patient. Alternatively, oradditionally, ADCC activity of the molecule of interest may be assessedin vivo, e.g., in an animal model such as that disclosed in Clynes etal., Proc. Natl. Acad. Sci. (USA) 95:652-656 (1998). Moreover,techniques for modulating (i.e., increasing or decreasing) the level ofADCC, and optionally CDC activity, of an antibody are well-known in theart. See, e.g., U.S. Pat. No. 6,194,551. Antibodies of the presentinvention preferably are capable or have been modified to have theability of inducing ADCC and/or CDC. Preferably, such assays todetermined ADCC function are practiced using humans effector cells toassess human ADCC function. Such assays may also include those intendedto screen for antibodies that induce, mediate, enhance, block cell deathby necrotic and/or apoptotic mechanisms. Such methods include assaysutilizing viable dyes, methods of detecting and analyzing caspaseactivity or cytochrome c release from the mitochondria, and assaysmeasuring DNA breaks can be used to assess the apoptotic activity ofcells cultured in vitro with an anti-CD22 antibody of interest.

For example, Annexin V or TdT-mediated dUTP nick-end labeling (TUNEL)assays can be carried out as described in Decker et al., Blood (USA)103:2718-2725 (2004) to detect apoptotic activity. The TUNEL assayinvolves culturing the cells of interest (e.g., B cells cultured in thepresence or absence of anti-CD22 antibodies) with fluorescein-labeleddUTP for incorporation into DNA strand breaks. The cells are thenprocessed for analysis by flow cytometry. The Annexin V assay detectsthe exposure of phosphatidylserine (PS) on the outside of the plasmamembrane using a fluorescein-conjugated antibody that specificallyrecognizes the exposed PS on the surface of apoptotic cells.Concurrently, a viable dye such as propidium iodide can be used toexclude late apoptotic cells. The cells are stained with the antibodyand are analyzed by flow cytometry. Moreover, techniques for assayingcells undergoing apoptosis are well-known in the art. See, e.g.,Chaouchi et al., J. Immunol., 154(7): 3096-104 (1995); Pedersen et al.,Blood, 99(4): 1314-1318 (2002); Alberts et al., Molecular Biology of theCell; Steensma et al., Methods Mol Med., 85: 323-32, (2003)).

5.17.3. Immunoconjugates and Fusion Proteins

According to certain aspects of the invention, therapeutic agents ortoxins can be conjugated to chimerized, human, or humanized anti-CD22antibodies for use in the compositions and methods of the invention. Incertain embodiments, these conjugates can be generated as fusionproteins. Examples of therapeutic agents and toxins include, but are notlimited to, members of the enediyne family of molecules, such ascalicheamicin and esperamicin. Chemical toxins can also be taken fromthe group consisting of duocarmycin (see, e.g., U.S. Pat. No. 5,703,080and U.S. Pat. No. 4,923,990), methotrexate, doxorubicin, melphalan,chlorambucil, ARA-C, vindesine, mitomycin C, cis-platinum, etoposide,bleomycin and 5-fluorouracil. Examples of chemotherapeutic agents alsoinclude Adriamycin, Doxorubicin, 5-Fluorouracil, Cytosine arabinoside(Ara-C), Cyclophosphamide, Thiotepa, Taxotere (docetaxel), Busulfan,Cytoxin, Taxol, Methotrexate, Cisplatin, Melphalan, Vinblastine,Bleomycin, Etoposide, Ifosfamide, Mitomycin C, Mitoxantrone,Vincreistine, Vinorelbine, Carboplatin, Teniposide, Daunomycin,Caminomycin, Aminopterin, Dactinomycin, Mitomycins, Esperamicins (see,U.S. Pat. No. 4,675,187), Melphalan, and other related nitrogenmustards.

Other toxins that can be used in the immunoconjugates of the inventioninclude poisonous lectins, plant toxins such as ricin, abrin, modeccin,botulina, and diphtheria toxins. Of course, combinations of the varioustoxins could also be coupled to one antibody molecule therebyaccommodating variable cytotoxicity. Illustrative of toxins which aresuitably employed in the combination therapies of the invention arericin, abrin, ribonuclease, DNase I, Staphylococcal enterotoxin-A,pokeweed anti-viral protein, gelonin, diphtherin toxin, Pseudomonasexotoxin, and Pseudomonas endotoxin. See, for example, Pastan et al.,Cell, 47:641 (1986), and Goldenberg et al., Cancer Journal forClinicians, 44:43 (1994). Enzymatically active toxins and fragmentsthereof which can be used include diphtheria A chain, non-binding activefragments of diphtheria toxin, exotoxin A chain (from Pseudomonasaeruginosa), ricin A chain, abrin A chain, modeccin A chain,alpha-sarcin, Aleurites fordii proteins, dianthin proteins, Phytolacaamericana proteins (PAPI, PAPII, and PAP-S), Momordica charantiainhibitor, curcin, crotin, Sapaonaria officinalis inhibitor, gelonin,mitogellin, restrictocin, phenomycin, enomycin and the tricothecenes.See, for example, WO 93/21232 published Oct. 28, 1993.

Suitable toxins and chemotherapeutic agents are described in Remington'sPharmaceutical Sciences, 19th Ed. (Mack Publishing Co. 1995), and inGoodman And Gilman's The Pharmacological Basis of Therapeutics, 7th Ed.(MacMillan Publishing Co. 1985). Other suitable toxins and/orchemotherapeutic agents are known to those of skill in the art.

The anti-CD22 antibody of the present invention may also be used inADEPT by conjugating the antibody to a prodrug-activating enzyme whichconverts a prodrug (e.g., a peptidyl chemotherapeutic agent, see, WO81/01145) to an active anti-cancer drug. See, for example, WO 88/07378and U.S. Pat. No. 4,975,278. The enzyme component of the immunoconjugateuseful for ADEPT includes any enzyme capable of acting on a prodrug insuch a way so as to covert it into its more active, cytotoxic form.

Enzymes that are useful in the method of this invention include, but arenot limited to, alkaline phosphatase useful for convertingphosphate-containing prodrugs into free drugs; arylsulfatase useful forconverting sulfate-containing prodrugs into free drugs; cytosinedeaminase useful for converting non-toxic 5-fluorocytosine into theanti-cancer drug, 5-fluorouracil; proteases, such as serratia protease,thermolysin, subtilisin, carboxypeptidases and cathepsins (such ascathepsins B and L), that are useful for converting peptide-containingprodrugs into free drugs; D-alanylcarboxypeptidases, useful forconverting prodrugs that contain D-amino acid substituents;carbohydrate-cleaving enzymes such as β-galactosidase and neuraminidaseuseful for converting glycosylated prodrugs into free drugs; β-lactamaseuseful for converting drugs derivatized with α-lactams into free drugs;and penicillin amidases, such as penicillin V amidase or penicillin Gamidase, useful for converting drugs derivatized at their aminenitrogens with phenoxyacetyl or phenylacetyl groups, respectively, intofree drugs. Alternatively, antibodies with enzymatic activity, alsoknown in the art as “abzymes,” can be used to convert the prodrugs ofthe invention into free active drugs (see, e.g., Massey, Nature328:457-458 (1987)). Antibody-abzyme conjugates can be prepared asdescribed herein for delivery of the abzyme as desired to portions of ahuman affected by a B cell malignancy.

The enzymes of this invention can be covalently bound to the antibody bytechniques well-known in the art such as the use of theheterobifunctional crosslinking reagents discussed above. Alternatively,fusion proteins comprising at least the antigen-binding region of anantibody of the invention linked to at least a functionally activeportion of an enzyme of the invention can be constructed usingrecombinant DNA techniques well-known in the art (see, e.g., Neubergeret al., Nature, 312:604-608 (1984)).

Covalent modifications of the anti-CD22 antibody of the invention areincluded within the scope of this invention. They may be made bychemical synthesis or by enzymatic or chemical cleavage of the antibody,if applicable. Other types of covalent modifications of the anti-CD22antibody are introduced into the molecule by reacting targeted aminoacid residues of the antibody with an organic derivatizing agent that iscapable of reacting with selected side chains or the N- or C-terminalresidues.

Cysteinyl residues most commonly are reacted with α-haloacetates (andcorresponding amines), such as chloroacetic acid or chloroacetamide, togive carboxymethyl or carboxyamidomethyl derivatives. Similarly,iodo-reagents may also be used. Cysteinyl residues also are derivatizedby reaction with bromotrifluoroacetone, α-bromo-β-(5-imidozoyl)propionicacid, chloroacetyl phosphate, N-alkylmaleimides, 3-nitro-2-pyridyldisulfide, methyl 2-pyridyl disulfide, p-chloromercuribenzoate,2-chloromercuri-4-nitrophenol, or chloro-7-nitrobenzo-2-oxa-1,3-diazole.

Histidyl residues are derivatized by reaction with diethylpyrocarbonateat pH 5.5-7.0 because this agent is relatively specific for the histidylside chain. Para-bromophenacyl bromide also is useful; the reaction ispreferably performed in 0.1 M sodium cacodylate at pH 6.0.

Lysyl and amino-terminal residues are reacted with succinic or othercarboxylic acid anhydrides. Derivatization with these agents has theeffect of reversing the charge of the lysinyl residues. Other suitablereagents for derivatizing α-amino-containing residues and/ore-amino-containing residues include imidoesters such as methylpicolinimidate, pyridoxal phosphate, pyridoxal, chloroborohydride,trinitrobenzenesulfonic acid, 0-methylisourea, 2,4-pentanedione, andtransaminase-catalyzed reaction with glyoxylate.

Arginyl residues are modified by reaction with one or severalconventional reagents, among them phenylglyoxal, 2,3-butanedione,1,2-cyclohexanedione, and ninhydrin. Derivatization of arginyl residuesgenerally requires that the reaction be performed in alkaline conditionsbecause of the high pKa of the guanidine functional group. Furthermore,these reagents may react with the ε-amino groups of lysine as well asthe arginine epsilon-amino group.

The specific modification of tyrosyl residues may be made, withparticular interest in introducing spectral labels into tyrosyl residuesby reaction with aromatic diazonium compounds or tetranitromethane. Mostcommonly, N-acetylimidizole and tetranitromethane are used to formO-acetyl tyrosyl species and 3-nitro derivatives, respectively. Tyrosylresidues are iodinated using ¹²⁵I or ¹³¹I to prepare labeled proteinsfor use in radioimmunoassay.

Carboxyl side groups (aspartyl or glutamyl) are selectively modified byreaction with carbodiimides (R—N═C═N—R′), where R and R′ are differentalkyl groups, such as 1-cyclohexyl-3-(2-morpholinyl-4-ethyl)carbodiimideor 1-ethyl-3-(4-azonia-4,4-dimethylpentyl)carbodiimide. Furthermore,aspartyl and glutamyl residues are converted to asparaginyl andglutaminyl residues by reaction with ammonium ions.

Glutaminyl and asparaginyl residues are frequently deamidated to thecorresponding glutamyl and aspartyl residues, respectively. Theseresidues are deamidated under neutral or basic conditions. Thedeamidated form of these residues falls within the scope of thisinvention.

Other modifications include hydroxylation of proline and lysine,phosphorylation of hydroxyl groups of seryl or threonyl residues,methylation of the α-amino groups of lysine, arginine, and histidineside chains (T. E. Creighton, Proteins: Structure and MolecularProperties, W.H. Freeman & Co., San Francisco, pp. 79-86 (1983)),acetylation of the N-terminal amine, and amidation of any C-terminalcarboxyl group.

Another type of covalent modification involves chemically orenzymatically coupling glycosides to the antibody. These procedures areadvantageous in that they do not require production of the antibody in ahost cell that has glycosylation capabilities for N- or O-linkedglycosylation. Depending on the coupling mode used, the sugar(s) may beattached to (a) arginine and histidine, (b) free carboxyl groups, (c)free sulfhydryl groups such as those of cysteine, (d) free hydroxylgroups such as those of serine, threonine, or hydroxyproline, (e)aromatic residues such as those of phenylalanine, tyrosine, ortryptophan, or (f) the amide group of glutamine. These methods aredescribed in WO 87/05330 published 11 Sep. 1987, and in Aplin andWriston, CRC Crit. Rev. Biochem., pp. 259-306 (1981).

5.18. Chemotherapeutic Combinations

In other embodiments, the anti-CD22 mAb of the invention can beadministered in combination with one or more additional chemotherapeuticagents. For example, “CVB” (1.5 g/m² cyclophosphamide, 200-400 mg/m²etoposide, and 150-200 mg/m² carmustine) can be used in the combinationtherapies of the invention. CVB is a regimen used to treat non-Hodgkin'slymphoma (Patti et al., Eur. J. Haematol., 51:18 (1993)). Other suitablecombination chemotherapeutic regimens are well-known to those of skillin the art. See, for example, Freedman et al., “Non-Hodgkin'sLymphomas,” in Cancer Medicine, Volume 2, 3rd Edition, Holland et al.(eds.), pp. 2028-2068 (Lea & Febiger 1993). As an illustration, firstgeneration chemotherapeutic regimens for treatment of intermediate-gradenon-Hodgkin's lymphoma include C-MOPP (cyclophosphamide, vincristine,procarbazine and prednisone) and CHOP (cyclophosphamide, doxorubicin,vincristine, and prednisone). A useful second generationchemotherapeutic regimen is m-BACOD (methotrexate, bleomycin,doxorubicin, cyclophosphamide, vincristine, dexamethasone, andleucovorin), while a suitable third generation regimen is MACOP-B(methotrexate, doxorubicin, cyclophosphamide, vincristine, prednisone,bleomycin, and leucovorin). Additional useful drugs include phenylbutyrate and brostatin-1.

According to the invention, cancer or one or more symptoms thereof maybe prevented, treated, managed or ameliorated by the administration ofan anti-CD22 mAb of the invention in combination with the administrationof one or more therapies such as, but not limited to, chemotherapies,radiation therapies, hormonal therapies, and/or biologicaltherapies/immunotherapies.

In a specific embodiment, the methods of the invention encompass theadministration of one or more angiogenesis antagonists such as but notlimited to: Angiostatin (plasminogen fragment); antiangiogenicantithrombin III; Angiozyme; ABT-627; Bay 12-9566; Benefin; Bevacizumab;BMS-275291; cartilage-derived inhibitor (CDI); CAI; CD59 complementfragment; CEP-7055; Col 3; Combretastatin A-4; Endostatin (collagenXVIII fragment); Fibronectin fragment; Gro-beta; Halofuginone;Heparinases; Heparin hexasaccharide fragment; HMV833; Human chorionicgonadotropin (hCG); IM-862; Interferon alpha/beta/gamma; Interferoninducible protein (IP-10); Interleukin-12; Kringle 5 (plasminogenfragment); Marimastat; Metalloproteinase inhibitors (TIMPs);2-Methoxyestradiol; MMI 270 (CGS 27023A); MoAb IMC-1C11; Neovastat;NM-3; Panzem; PI-88; Placental ribonuclease inhibitor; Plasminogenactivator inhibitor; Platelet factor-4 (PF4); Prinomastat; Prolactin 16kD fragment; Proliferin-related protein (PRP); PTK 787/ZK 222594;Retinoids; Solimastat; Squalamine; SS 3304; SU 5416; SU6668; SU11248;Tetrahydrocortisol-S; tetrathiomolybdate; thalidomide; Thrombospondin-1(TSP-1); TNP-470; Transforming growth factor-beta (TGF-b);Vasculostatin; Vasostatin (calreticulin fragment); ZD6126; ZD 6474;farnesyl transferase inhibitors (FTI); and bisphosphonates (such as butare not limited to, alendronate, clodronate, etidronate, ibandronate,pamidronate, risedronate, tiludronate, and zoledronate).

In a specific embodiment, the methods of the invention encompass theadministration of one or more immunomodulatory agents, such as but notlimited to, chemotherapeutic agents and non-chemotherapeuticimmunomodulatory agents. Non-limiting examples of chemotherapeuticagents include methotrexate, cyclosporin A, leflunomide, cisplatin,ifosfamide, taxanes such as taxol and paclitaxol, topoisomerase Iinhibitors (e.g., CPT-11, topotecan, 9-AC, and GG-211), gemcitabine,vinorelbine, oxaliplatin, 5-fluorouracil (5-FU), leucovorin,vinorelbine, temodal, cytochalasin B, gramicidin D, emetine, mitomycin,etoposide, tenoposide, vincristine, vinblastine, colchicin, doxorubicin,daunorubicin, dihydroxy anthracin dione, mitoxantrone, mithramycin,actinomycin D, 1-dehydrotestosterone, glucocorticoids, procaine,tetracaine, lidocaine, propranolol, and puromycin homologs, and cytoxan.Examples of non-chemotherapeutic immunomodulatory agents include, butare not limited to, anti-T cell receptor antibodies (e.g., anti-CD4antibodies (e.g., cM-T412 (Boeringer), IDEC-CE9.1® ((IDEC and SKB), mAB4162W94, Orthoclone and OKTcdr4a (Janssen-Cilag)), anti-CD3 antibodies(e.g., Nuvion (Product Design Labs), OKT3 (Johnson & Johnson), orRituxan (IDEC)), anti-CD5 antibodies (e.g., an anti-CD5 ricin-linkedimmunoconjugate), anti-CD7 antibodies (e.g., CHH-380 (Novartis)),anti-CD8 antibodies, anti-CD40 ligand monoclonal antibodies (e.g.,IDEC-131 (IDEC)), anti-CD52 antibodies (e.g., CAMPATH 1H (Ilex)),anti-CD2 antibodies (e.g., MEDI-507 (MedImmune, Inc., InternationalPublication Nos. WO 02/098370 and WO 02/069904), anti-CD11a antibodies(e.g., Xanelim (Genentech)), and anti-B7 antibodies (e.g., IDEC-114)(IDEC)); anti-cytokine receptor antibodies (e.g., anti-IFN receptorantibodies, anti-IL-2 receptor antibodies (e.g., Zenapax (Protein DesignLabs)), anti-IL-4 receptor antibodies, anti-IL-6 receptor antibodies,anti-IL-10 receptor antibodies, and anti-IL-12 receptor antibodies),anti-cytokine antibodies (e.g., anti-IFN antibodies, anti-TNF-αantibodies, anti-IL-1β antibodies, anti-IL-6 antibodies, anti-IL-8antibodies (e.g., ABX-IL-8 (Abgenix)), anti-IL-12 antibodies andanti-IL-23 antibodies)); CTLA4-immunoglobulin; LFA-3TIP (Biogen,International Publication No. WO 93/08656 and U.S. Pat. No. 6,162,432);soluble cytokine receptors (e.g., the extracellular domain of a TNF-αreceptor or a fragment thereof, the extracellular domain of an IL-1βreceptor or a fragment thereof, and the extracellular domain of an IL-6receptor or a fragment thereof); cytokines or fragments thereof (e.g.,interleukin (IL)-2, IL-3, IL-4, IL-5, IL-6, IL-7, IL-8, IL-9, IL-10,IL-11, IL-12, IL-15, IL-23, TNF-α, TNF-β, interferon (IFN)-α, IFN-β,IFN-γ, and GM-CSF); and anti-cytokine antibodies (e.g., anti-IL-2antibodies, anti-IL-4 antibodies, anti-IL-6 antibodies, anti-IL-10antibodies, anti-IL-12 antibodies, anti-IL-15 antibodies, anti-TNF-αantibodies, and anti-IFN-γ antibodies), and antibodies thatimmunospecifically bind to tumor-associated antigens (e.g., Herceptin®).In certain embodiments, an immunomodulatory agent is an immunomodulatoryagent other than a chemotherapeutic agent. In other embodiments animmunomodulatory agent is an immunomodulatory agent other than acytokine or hemapoietic such as IL-1, IL-2, IL-4, IL-12, IL-15, TNF,IFN-α, IFN-β, IFN-γ, M-CSF, G-CSF, IL-3 or erythropoietin. In yet otherembodiments, an immunomodulatory agent is an agent other than achemotherapeutic agent and a cytokine or hemapoietic factor.

In a specific embodiment, the methods of the invention encompass theadministration of one or more anti-inflammatory agents, such as but notlimited to, non-steroidal anti-inflammatory drugs (NSAIDs), steroidalanti-inflammatory drugs, beta-agonists, anticholingeric agents, andmethyl xanthines. Examples of NSAIDs include, but are not limited to,aspirin, ibuprofen, celecoxib (CELEBREX™), diclofenac (VOLTAREN™),etodolac (LODINE™), fenoprofen (NALFON™), indomethacin (INDOCIN™),ketoralac (TORADOL™), oxaprozin (DAYPRO™), nabumentone (RELAFEN™),sulindac (CLINORIL™), tolmentin (TOLECTIN™), rofecoxib (VIOXX™),naproxen (ALEVE™, NAPROSYN™), ketoprofen (ACTRON™) and nabumetone(RELAFEN™). Such NSAIDs function by inhibiting a cyclooxygenase enzyme(e.g., COX-1 and/or COX-2). Examples of steroidal anti-inflammatorydrugs include, but are not limited to, glucocorticoids, dexamethasone(DECADRON™), cortisone, hydrocortisone, prednisone (DELTASONE™),prednisolone, triamcinolone, azulfidine, and eicosanoids such asprostaglandins, thromboxanes, and leukotrienes.

In another specific embodiment, the methods of the invention encompassthe administration of one or more antiviral agents (e.g., amantadine,ribavirin, rimantadine, acyclovir, famciclovir, foscarnet, ganciclovir,trifluridine, vidarabine, didanosine, stavudine, zalcitabine,zidovudine, interferon), antibiotics (e.g., dactinomycin (formerlyactinomycin), bleomycin, mithramycin, and anthramycin (AMC)),anti-emetics (e.g., alprazolam, dexamethoasone, domperidone, dronabinol,droperidol, granisetron, haloperidol, haloperidol, iorazepam,methylprednisolone, metoclopramide, nabilone, ondansetron,prochlorperazine), anti-fungal agents (e.g., amphotericin, clotrimazole,econazole, fluconazole, flucytosine, griseofulvin, itraconazole,ketoconazole, miconazole and nystatin), anti-parasite agents (e.g.,dehydroemetine, diloxanide furoate, emetine, mefloquine, melarsoprol,metronidazole, nifurtimox, paromomycin, pentabidine, pentamidineisethionate, primaquine, quinacrine, quinidine) or a combinationthereof.

Specific examples of anti-cancer agents that can be used in the variousembodiments of the invention, including pharmaceutical compositions anddosage forms and kits of the invention, include, but are not limited to:acivicin; aclarubicin; acodazole hydrochloride; acronine; adozelesin;aldesleukin; altretamine; ambomycin; ametantrone acetate;aminoglutethimide; amsacrine; anastrozole; anthramycin; asparaginase;asperlin; azacitidine; azetepa; azotomycin; batimastat; benzodepa;bicalutamide; bisantrene hydrochloride; bisnafide dimesylate; bizelesin;bleomycin sulfate; brequinar sodium; bropirimine; busulfan;cactinomycin; calusterone; caracemide; carbetimer; carboplatin;carmustine; carubicin hydrochloride; carzelesin; cedefingol;chlorambucil; cirolemycin; cisplatin; cladribine; crisnatol mesylate;cyclophosphamide; cytarabine; dacarbazine; dactinomycin; daunorubicinhydrochloride; decitabine; dexormaplatin; dezaguanine; dezaguaninemesylate; diaziquone; docetaxel; doxorubicin; doxorubicin hydrochloride;droloxifene; droloxifene citrate; dromostanolone propionate; duazomycin;edatrexate; eflornithine hydrochloride; elsamitrucin; enloplatin;enpromate; epipropidine; epirubicin hydrochloride; erbulozole;esorubicin hydrochloride; estramustine; estramustine phosphate sodium;etanidazole; etoposide; etoposide phosphate; etoprine; fadrozolehydrochloride; fazarabine; fenretinide; floxuridine; fludarabinephosphate; fluorouracil; flurocitabine; fosquidone; fostriecin sodium;gemcitabine; gemcitabine hydrochloride; hydroxyurea; idarubicinhydrochloride; ifosfamide; ilmofosine; interleukin II (includingrecombinant interleukin II, or rIL2), interferon alpha-2a; interferonalpha-2b; interferon alpha-n1 interferon alpha-n3; interferon beta-I a;interferon gamma-I b; iproplatin; irinotecan hydrochloride; lanreotideacetate; letrozole; leuprolide acetate; liarozole hydrochloride;lometrexol sodium; lomustine; losoxantrone hydrochloride; masoprocol;maytansine; mechlorethamine hydrochloride; megestrol acetate;melengestrol acetate; melphalan; menogaril; mercaptopurine;methotrexate; methotrexate sodium; metoprine; meturedepa; mitindomide;mitocarcin; mitocromin; mitogillin; mitomalcin; mitomycin; mitosper;mitotane; mitoxantrone hydrochloride; mycophenolic acid; nocodazole;nogalamycin; ormaplatin; oxisuran; paclitaxel; pegaspargase; peliomycin;pentamustine; peplomycin sulfate; perfosfamide; pipobroman; piposulfan;piroxantrone hydrochloride; plicamycin; plomestane; porfimer sodium;porfiromycin; prednimustine; procarbazine hydrochloride; puromycin;puromycin hydrochloride; pyrazofurin; riboprine; rogletimide; safingol;safingol hydrochloride; semustine; simtrazene; sparfosate sodium;sparsomycin; spirogermanium hydrochloride; spiromustine; spiroplatin;streptonigrin; streptozocin; sulofenur; talisomycin; tecogalan sodium;tegafur; teloxantrone hydrochloride; temoporfin; teniposide; teroxirone;testolactone; thiamiprine; thioguanine; thiotepa; tiazofurin;tirapazamine; toremifene citrate; trestolone acetate; triciribinephosphate; trimetrexate; trimetrexate glucuronate; triptorelin;tubulozole hydrochloride; uracil mustard; uredepa; vapreotide;verteporfin; vinblastine sulfate; vincristine sulfate; vindesine;vindesine sulfate; vinepidine sulfate; vinglycinate sulfate;vinleurosine sulfate; vinorelbine tartrate; vinrosidine sulfate;vinzolidine sulfate; vorozole; zeniplatin; zinostatin; zorubicinhydrochloride. Other anti-cancer drugs include, but are not limited to:20-epi-1,25 dihydroxyvitamin D3; 5-ethynyluracil; abiraterone;aclarubicin; acylfulvene; adecypenol; adozelesin; aldesleukin; ALL-TKantagonists; altretamine; ambamustine; amidox; amifostine;aminolevulinic acid; amrubicin; amsacrine; anagrelide; anastrozole;andrographolide; angiogenesis inhibitors; antagonist D; antagonist G;antarelix; anti-dorsalizing morphogenetic protein-1; antiandrogen,prostatic carcinoma; antiestrogen; antineoplaston; antisenseoligonucleotides; aphidicolin glycinate; apoptosis gene modulators;apoptosis regulators; apurinic acid; ara-CDP-DL-PTBA; argininedeaminase; asulacrine; atamestane; atrimustine; axinastatin 1;axinastatin 2; axinastatin 3; azasetron; azatoxin; azatyrosine; baccatinIII derivatives; balanol; batimastat; BCR/ABL antagonists;benzochlorins; benzoylstaurosporine; beta lactam derivatives;beta-alethine; betaclamycin B; betulinic acid; bFGF inhibitor;bicalutamide; bisantrene; bisaziridinylspermine; bisnafide; bistrateneA; bizelesin; breflate; bropirimine; budotitane; buthionine sulfoximine;calcipotriol; calphostin C; camptothecin derivatives; canarypox IL-2;capecitabine; carboxamide-amino-triazole; carboxyamidotriazole; CaRestM3; CARN 700; cartilage derived inhibitor; carzelesin; casein kinaseinhibitors (ICOS); castanospermine; cecropin B; cetrorelix; chlorlns;chloroquinoxaline sulfonamide; cicaprost; cis-porphyrin; cladribine;clomifene analogues; clotrimazole; collismycin A; collismycin B;combretastatin A4; combretastatin analogue; conagenin; crambescidin 816;crisnatol; cryptophycin 8; cryptophycin A derivatives; curacin A;cyclopentanthraquinones; cycloplatam; cypemycin; cytarabine ocfosfate;cytolytic factor; cytostatin; dacliximab; decitabine; dehydrodidemnin B;deslorelin; dexamethasone; dexifosfamide; dexrazoxane; dexverapamil;diaziquone; didemnin B; didox; diethylnorspermine;dihydro-5-azacytidine; dihydrotaxol, 9-; dioxamycin; diphenylspiromustine; docetaxel; docosanol; dolasetron; doxifluridine;droloxifene; dronabinol; duocarmycin SA; ebselen; ecomustine;edelfosine; edrecolomab; eflornithine; elemene; emitefur; epirubicin;epristeride; estramustine analogue; estrogen agonists; estrogenantagonists; etanidazole; etoposide phosphate; exemestane; fadrozole;fazarabine; fenretinide; filgrastim; finasteride; flavopiridol;flezelastine; fluasterone; fludarabine; fluorodaunorunicinhydrochloride; forfenimex; formestane; fostriecin; fotemustine;gadolinium texaphyrin; gallium nitrate; galocitabine; ganirelix;gelatinase inhibitors; gemcitabine; glutathione inhibitors; hepsulfam;heregulin; hexamethylene bisacetamide; hypericin; ibandronic acid;idarubicin; idoxifene; idramantone; ilmofosine; ilomastat;imidazoacridones; imiquimod; immunostimulant peptides; insulin-likegrowth factor-I receptor inhibitor; interferon agonists; interferons;interleukins; iobenguane; iododoxorubicin; ipomeanol, 4-; iroplact;irsogladine; isobengazole; isohomohalicondrin B; itasetron;jasplakinolide; kahalalide F; lamellarin-N triacetate; lanreotide;leinamycin; lenograstim; lentinan sulfate; leptolstatin; letrozole;leukemia inhibiting factor; leukocyte alpha interferon;leuprolide+estrogen+progesterone; leuprorelin; levamisole; liarozole;linear polyamine analogue; lipophilic disaccharide peptide; lipophilicplatinum compounds; lissoclinamide 7; lobaplatin; lombricine;lometrexol; lonidamine; losoxantrone; HMG-CoA reductase inhibitor (suchas but not limited to, Lovastatin, Pravastatin, Fluvastatin, Statin,Simvastatin, and Atorvastatin); loxoribine; lurtotecan; lutetiumtexaphyrin; lysofylline; lytic peptides; maitansine; mannostatin A;marimastat; masoprocol; maspin; matrilysin inhibitors; matrixmetalloproteinase inhibitors; menogaril; merbarone; meterelin;methioninase; metoclopramide; MIF inhibitor; mifepristone; miltefosine;mirimostim; mismatched double stranded RNA; mitoguazone; mitolactol;mitomycin analogues; mitonafide; mitotoxin fibroblast growthfactor-saporin; mitoxantrone; mofarotene; molgramostim; monoclonalantibody, human chorionic gonadotrophin; monophosphoryl lipidA+myobacterium cell wall sk; mopidamol; multiple drug resistance geneinhibitor; multiple tumor suppressor 1-based therapy; mustard anticanceragent; mycaperoxide B; mycobacterial cell wall extract; myriaporone;N-acetyldinaline; N-substituted benzamides; nafarelin; nagrestip;naloxone+pentazocine; napavin; naphterpin; nartograstim; nedaplatin;nemorubicin; neridronic acid; neutral endopeptidase; nilutamide;nisamycin; nitric oxide modulators; nitroxide antioxidant; nitrullyn;O6-benzylguanine; octreotide; okicenone; oligonucleotides; onapristone;ondansetron; ondansetron; oracin; oral cytokine inducer; ormaplatin;osaterone; oxaliplatin; oxaunomycin; paclitaxel; paclitaxel analogues;paclitaxel derivatives; palauamine; palmitoylrhizoxin; pamidronic acid;panaxytriol; panomifene; parabactin; pazelliptine; pegaspargase;peldesine; pentosan polysulfate sodium; pentostatin; pentrozole;perflubron; perfosfamide; perillyl alcohol; phenazinomycin;phenylacetate; phosphatase inhibitors; picibanil; pilocarpinehydrochloride; pirarubicin; piritrexim; placetin A; placetin B;plasminogen activator inhibitor; platinum complex; platinum compounds;platinum-triamine complex; porfimer sodium; porfiromycin; prednisone;propyl bis-acridone; prostaglandin J2; proteasome inhibitors; proteinA-based immune modulator; protein kinase C inhibitor; protein kinase Cinhibitors, microalgal; protein tyrosine phosphatase inhibitors; purinenucleoside phosphorylase inhibitors; purpurins; pyrazoloacridine;pyridoxylated hemoglobin polyoxyethylene conjugate; raf antagonists;raltitrexed; ramosetron; ras farnesyl protein transferase inhibitors;ras inhibitors; ras-GAP inhibitor; retelliptine demethylated; rhenium Re186 etidronate; rhizoxin; ribozymes; RII retinamide; rogletimide;rohitukine; romurtide; roquinimex; rubiginone B1; ruboxyl; safingol;saintopin; SarCNU; sarcophytol A; sargramostim; Sdi 1 mimetics;semustine; senescence derived inhibitor 1; sense oligonucleotides;signal transduction inhibitors; signal transduction modulators; singlechain antigen binding protein; sizofiran; sobuzoxane; sodiumborocaptate; sodium phenylacetate; solverol; somatomedin bindingprotein; sonermin; sparfosic acid; spicamycin D; spiromustine;splenopentin; spongistatin 1; squalamine; stem cell inhibitor; stem-celldivision inhibitors; stipiamide; stromelysin inhibitors; sulfinosine;superactive vasoactive intestinal peptide antagonist; suradista;suramin; swainsonine; synthetic glycosaminoglycans; tallimustine;tamoxifen methiodide; tauromustine; tazarotene; tecogalan sodium;tegafur; tellurapyrylium; telomerase inhibitors; temoporfin;temozolomide; teniposide; tetrachlorodecaoxide; tetrazomine;thaliblastine; thiocoraline; thrombopoietin; thrombopoietin mimetic;thymalfasin; thymopoietin receptor agonist; thymotrinan; thyroidstimulating hormone; tin ethyl etiopurpurin; tirapazamine; titanocenebichloride; topsentin; toremifene; totipotent stem cell factor;translation inhibitors; tretinoin; triacetyluridine; triciribine;trimetrexate; triptorelin; tropisetron; turosteride; tyrosine kinaseinhibitors; tyrphostins; UBC inhibitors; ubenimex; urogenitalsinus-derived growth inhibitory factor; urokinase receptor antagonists;vapreotide; variolin B; vector system, erythrocyte gene therapy;velaresol; veramine; verdins; verteporfin; vinorelbine; vinxaltine;Vitaxin®; vorozole; zanoterone; zeniplatin; zilascorb; and zinostatinstimalamer. Preferred additional anti-cancer drugs are 5-fluorouraciland leucovorin. These two agents are particularly useful when used inmethods employing thalidomide and a topoisomerase inhibitor. In specificembodiments, a anti-cancer agent is not a chemotherapeutic agent.

In more particular embodiments, the present invention also comprises theadministration of an anti-CD22 mAb of the invention in combination withthe administration of one or more therapies such as, but not limited toanti-cancer agents such as those disclosed in Table 1, preferably forthe treatment of breast, ovary, melanoma, prostate, colon and lungcancers as described above. When used in a combination therapy, thedosages and/or the frequency of administration listed in Table 1 may bedecreased.

TABLE 1 Therapeutic Agent Dose/Administration/Formulation doxorubicinIntravenous 60-75 mg/m² on Day 1 21 day intervals hydrochloride(Adriamycin RDF ® and Adriamycin PFS ® epirubicin Intravenous 100-120mg/m² on Day 1 of 3-4 week cycles hydrochloride each cycle or(Ellence ™) divided equally and given on Days 1-8 of the cyclefluorousacil Intravenous How supplied: 5 mL and 10 mL vials (containing250 and 500 mg flourouracil respectively) docetaxel Intravenous 60-100mg/m² over 1 hour Once every 3 weeks (Taxotere ®) paclitaxel Intravenous175 mg/m² over 3 hours Every 3 weeks for (Taxol ®) 4 courses(administered sequentially to doxorubicin-containing combinationchemotherapy) tamoxifen citrate Oral 20-40 mg Daily (Nolvadex ®)(tablet) Dosages greater than 20 mg should be given in divided doses(morning and evening) leucovorin intravenous How supplied: Dosage isunclear from calcium for or 350 mg vial text. PDR 3610 injectionintramuscular injection luprolide acetate single 1 mg (0.2 mL or 20 unitOnce a day Lupron ®) subcutaneous mark) injection flutamide Oral 50 mg 3times a day at 8 hour (Eulexin ®) (capsule) (capsules contain 125 mgintervals (total daily flutamide each) dosage 750 mg) nilutamide Oral300 mg or 150 mg 300 mg once a day for 30 (Nilandron ®) (tablet)(tablets contain 50 or 150 mg days followed by 150 mg nilutamide each)once a day bicalutamide Oral 50 mg Once a day (Casodex ®) (tablet)(tablets contain 50 mg bicalutamide each) progesterone Injection USP insesame oil 50 mg/mL ketoconazole Cream 2% cream applied once or(Nizoral ®) twice daily depending on symptoms prednisone Oral Initialdosage may vary from (tablet) 5 mg to 60 mg per day depending on thespecific disease entity being treated. estramustine Oral 14 mg/kg ofbody weight Daily given in 3 or 4 phosphate (capsule) (i.e. one 140 mgcapsule for divided doses sodium each 10 kg or 22 lb of body (Emcyt ®)weight) etoposide or Intravenous 5 mL of 20 mg/mL solution VP-16 (100mg) dacarbazine Intravenous 2-4.5 mg/kg Once a day for 10 days.(DTIC-Dome ®) May be repeated at 4 week intervals polifeprosan 20 waferplaced 8 wafers, each containing 7.7 with carmustine in resection mg ofcarmustine, for a total implant (BCNU) cavity of 61.6 mg, if size andshape (nitrosourea) of resection cavity allows (Gliadel ®) cisplatinInjection [n/a in PDR 861] How supplied: solution of 1 mg/mL inmulti-dose vials of 50 mL and 100 mL mitomycin Injection supplied in 5mg and 20 mg vials (containing 5 mg and 20 mg mitomycin) gemcitabine HClIntravenous For NSCLC-2 schedules 4 week schedule- (Gemzar ®) have beeninvestigated and Days 1, 8 and 15 of each the optimum schedule has28-day cycle. Cisplatin not been determined intravenously at 100 4 weekschedule- mg/m² on day 1 after the administration intravenously infusionof Gemzar. at 1000 mg/m² over 30 3 week schedule- minutes on 3 weekschedule- Days 1 and 8 of each 21 Gemzar administered day cycle.Cisplatin at intravenously at 1250 mg/m² dosage of 100 mg/m² over 30minutes administered intravenously after administration of Gemzar onday 1. carboplatin Intravenous Single agent therapy: Every 4 weeks(Paraplatin ®) 360 mg/m² I.V. on day 1 (infusion lasting 15 minutes orlonger) Other dosage calculations: Combination therapy withcyclophosphamide, Dose adjustment recommendations, Formula dosing, etc.ifosamide Intravenous 1.2 g/m² daily 5 consecutive days (Ifex ®) Repeatevery 3 weeks or after recovery from hematologic toxicity topotecanIntravenous 1.5 mg/m² by intravenous 5 consecutive days, hydrochlorideinfusion over 30 minutes starting on day 1 of 21 day (Hycamtin ®) dailycourse Bisphosphonates Intravenous 60 mg or 90 mg single Pamidronate orOral infusion over 4-24 hours to Alendronate take with correcthypercalcemia in Risedronate 6-8 oz cancer patients water. 5 mg/d dailyfor 2 years and then 10 mg/d for 9 month to prevent or control boneresorption. 5.0 mg to prevent or control bone resorption. LovastatinOral 10-80 mg/day in single or (Mevacor ™) two divided dose.

The invention also encompasses administration of an anti-CD22 mAb of theinvention in combination with radiation therapy comprising the use ofx-rays, gamma rays and other sources of radiation to destroy the cancercells. In preferred embodiments, the radiation treatment is administeredas external beam radiation or teletherapy wherein the radiation isdirected from a remote source. In other preferred embodiments, theradiation treatment is administered as internal therapy or brachytherapywherein a radioactive source is placed inside the body close to cancercells or a tumor mass.

Cancer therapies and their dosages, routes of administration andrecommended usage are known in the art and have been described in suchliterature as the Physician's Desk Reference (56^(th) ed., 2002).

5.19. Pharmaceutical Compositions

The invention also relates to immunotherapeutic compositions and methodsfor the treatment of B cell diseases and disorders in human subjects,such as, but not limited to, B cell malignancies, to immunotherapeuticcompositions and methods for the treatment and prevention of GVHD, graftrejection, and post-transplant lymphocyte proliferative disorder inhuman transplant recipients, and to immunotherapeutic compositions andmethods for the treatment of autoimmune diseases and disorders in humansubjects, using therapeutic antibodies that bind to the CD22 antigen andpreferably mediate human ADCC.

The present invention relates to pharmaceutical compositions comprisinghuman, humanized, or chimeric anti-CD22 antibodies of the IgG1 or IgG3human isotype. The present invention also relates to pharmaceuticalcompositions comprising human or humanized anti-CD22 antibodies of theIgG2 or IgG4 human isotype that preferably mediate human ADCC. Incertain embodiments, the present invention also relates topharmaceutical compositions comprising monoclonal human, humanized, orchimerized anti-CD22 antibodies that can be produced by means known inthe art.

Therapeutic formulations and regimens are described for treating humansubjects diagnosed with B cell malignancies that derive from B cells andtheir precursors, including but not limited to, acute lymphoblasticleukemia (ALL), Hodgkin's lymphomas, non-Hodgkin's lymphomas, B cellchronic lymphocytic leukemia (CLL), multiple myeloma, follicularlymphoma, mantle cell lymphoma, pro-lymphocytic leukemia, hairy cellleukemia, common acute lymphocytic leukemia and some Null-acutelymphoblastic leukemia.

In other particular embodiments, the anti-CD22 antibodies of theinvention mediate ADCC, complement-dependent cellular cytoxicity, orapoptosis. The compositions and methods of the present invention alsohave the advantage of targeting a wider population of B cells than otherB cell directed immunotherapies. For example, anti-CD22 antibodies ofthe present invention are effective to target bone marrow cells,circulating B cells, and mature, antibody-secreting B cells.Accordingly, the methods and compositions of the invention are effectiveto reduce or deplete circulating B cells as well as circulatingimmunoglobulin.

Accordingly, in one aspect, the invention provides compositions andmethods for the treatment and prevention of GVHD, graft rejection, andpost-transplantation lymphoproliferative disorder, which are associatedwith fewer and/or less severe complications than less-targetedtherapeutic agents and regimens. In one embodiment, the compositions andmethods of the invention are used with lower doses of traditionaltherapeutic agents than would be possible in the absence of the methodsand compositions of the invention. In another embodiment, thecompositions and methods of the invention obviate the need for a moresevere form of therapy, such as radiation therapy, high-dosechemotherapy, or splenectomy.

In certain embodiments, the anti-CD22 antibodies and compositions of theinvention may be administered to a transplant recipient patient prior toor following transplantation, alone or in combination with othertherapeutic agents or regimens for the treatment or prevention of GVHDand graft rejection. For example, the anti-CD22 antibodies andcompositions of the invention may be used to deplete alloantibodies froma transplant recipient prior to or following transplantation of anallogeneic graft. The anti-CD22 antibodies and compositions of theinvention may also be used to deplete antibody-producing cells from thegraft ex vivo, prior to transplantation, or in the donor, or asprophylaxis against GVHD and graft rejection.

5.20. Pharmaceutical Formulations, Administration and Dosing

The pharmaceutical formulations of the invention contain as the activeingredient human, humanized, or chimeric anti-CD22 antibodies. Theformulations contain naked antibody, immunoconjugate, or fusion proteinin an amount effective for producing the desired response in a unit ofweight or volume suitable for administration to a human patient, and arepreferably sterile. The response can, for example, be measured bydetermining the physiological effects of the anti-CD22 antibodycomposition, such as, but not limited to, circulating B cell depletion,tissue B cell depletion, regression of a B cell malignancy, or decreaseof disease symptoms. Other assays will be known to one of ordinary skillin the art and can be employed for measuring the level of the response.

5.20.1. Pharmaceutical Formulations

An anti-CD22 antibody composition may be formulated with apharmaceutically acceptable carrier. The term “pharmaceuticallyacceptable” means one or more non-toxic materials that do not interferewith the effectiveness of the biological activity of the activeingredients. Such preparations may routinely contain salts, bufferingagents, preservatives, compatible carriers, and optionally othertherapeutic agents. Such pharmaceutically acceptable preparations mayalso routinely contain compatible solid or liquid fillers, diluents orencapsulating substances which are suitable for administration into ahuman. When used in medicine, the salts should be pharmaceuticallyacceptable, but non-pharmaceutically acceptable salts may convenientlybe used to prepare pharmaceutically acceptable salts thereof and are notexcluded from the scope of the invention. Such pharmacologically andpharmaceutically acceptable salts include, but are not limited to, thoseprepared from the following acids: hydrochloric, hydrobromic, sulfuric,nitric, phosphoric, maleic, acetic, salicylic, citric, boric, formic,malonic, succinic, and the like. Also, pharmaceutically acceptable saltscan be prepared as alkaline metal or alkaline earth salts, such assodium, potassium or calcium salts. The term “carrier” denotes anorganic or inorganic ingredient, natural or synthetic, with which theactive ingredient is combined to facilitate the application. Thecomponents of the pharmaceutical compositions also are capable of beingco-mingled with the antibodies of the present invention, and with eachother, in a manner such that there is no interaction which wouldsubstantially impair the desired pharmaceutical efficacy.

According to certain aspects of the invention, the anti-CD22 antibodycompositions can be prepared for storage by mixing the antibody orimmunoconjugate having the desired degree of purity with optionalphysiologically acceptable carriers, excipients or stabilizers(Remington's Pharmaceutical Sciences, 16th edition, Osol, A. Ed.(1999)), in the form of lyophilized formulations or aqueous solutions.Acceptable carriers, excipients, or stabilizers are nontoxic torecipients at the dosages and concentrations employed, and includebuffers such as phosphate, citrate, and other organic acids;antioxidants including ascorbic acid and methionine; preservatives (suchas octadecyldimethylbenzyl ammonium chloride; hexamethonium chloride;benzalkonium chloride, benzethonium chloride; phenol, butyl or benzylalcohol; alkyl parabens such as methyl or propyl paraben; catechol;resorcinol; cyclohexanol; 3-pentanol; and m-cresol); low molecularweight (less than about 10 residues) polypeptide; proteins, such asserum albumin, gelatin, or immunoglobulins; hydrophilic polymers such aspolyvinylpyrolidone; amino acids such as glycine, glutamine, asparagine,histidine, arginine, or lysine; monosaccharides, disaccharides, andother carbohydrates including glucose, mannose, or dextrins; chelatingagents such as EDTA; sugars such as sucrose, mannitol, trehalose orsorbitol; salt-forming counter-ions such as sodium; metal complexes(e.g., Zn-protein complexes); and/or non-ionic surfactants such asTWEEN, PLURONICS™ or polyethylene glycol (PEG).

The anti-CD22 antibody compositions also may contain, optionally,suitable preservatives, such as: benzalkonium chloride; chlorobutanol;parabens and thimerosal.

The anti-CD22 antibody compositions may conveniently be presented inunit dosage form and may be prepared by any of the methods well-known inthe art of pharmacy. All methods include the step of bringing the activeagent into association with a carrier which constitutes one or moreaccessory ingredients. In general, the compositions are prepared byuniformly and intimately bringing the active compound into associationwith a liquid carrier, a finely divided solid carrier, or both, andthen, if necessary, shaping the product.

Compositions suitable for parenteral administration convenientlycomprise a sterile aqueous or non-aqueous preparation of anti-CD22antibody, which is preferably isotonic with the blood of the recipient.This preparation may be formulated according to known methods usingsuitable dispersing or wetting agents and suspending agents. The sterileinjectable preparation also may be a sterile injectable solution orsuspension in a non-toxic parenterally acceptable diluent or solvent,for example, as a solution in 1,3-butanediol. Among the acceptablevehicles and solvents that may be employed are water, Ringer's solution,and isotonic sodium chloride solution. In addition, sterile, fixed oilsare conventionally employed as a solvent or suspending medium. For thispurpose any bland fixed oil may be employed including synthetic mono- ordi-glycerides. In addition, fatty acids such as oleic acid may be usedin the preparation of injectables. Carrier formulation suitable fororal, subcutaneous, intravenous, intramuscular, etc. administration canbe found in Remington's Pharmaceutical Sciences, Mack Publishing Co.,Easton, Pa. In certain embodiments, carrier formulation suitable forvarious routes of administration can be the same or similar to thatdescribed for RITUXAN™. See, Physicians' Desk Reference (MedicalEconomics Company, Inc., Montvale, N.J., 2005), pp. 958-960 and1354-1357, which is incorporated herein by reference in its entirety. Incertain embodiments of the invention, the anti-CD22 antibodycompositions are formulated for intravenous administration with sodiumchloride, sodium citrate dihydrate, polysorbate 80, and sterile waterwhere the pH of the composition is adjusted to approximately 6.5. Thoseof skill in the art are aware that intravenous injection provides auseful mode of administration due to the thoroughness of the circulationin rapidly distributing antibodies. Intravenous administration, however,is subject to limitation by a vascular barrier comprising endothelialcells of the vasculature and the subendothelial matrix. Still, thevascular barrier is a more notable problem for the uptake of therapeuticantibodies by solid tumors. Lymphomas have relatively high blood flowrates, contributing to effective antibody delivery. Intralymphaticroutes of administration, such as subcutaneous or intramuscularinjection, or by catheterization of lymphatic vessels, also provide auseful means of treating B cell lymphomas. In preferred embodiments,anti-CD22 antibodies of the compositions and methods of the inventionare self-administered subcutaneously. In such preferred embodiments, thecomposition is formulated as a lyophilized drug or in a liquid buffer(e.g., PBS and/or citrate) at about 50 mg/mL.

The formulation herein may also contain more than one active compound asnecessary for the particular indication being treated, preferably thosewith complementary activities that do not adversely affect each other.For example, it may be desirable to further provide an immunosuppressiveagent. Such molecules are suitably present in combination in amountsthat are effective for the purpose intended.

The active ingredients may also be entrapped in microcapsule prepared,for example, by coacervation techniques or by interfacialpolymerization, for example, hydroxymethylcellulose orgelatin-microcapsule and poly-(methylmethacylate) microcapsule,respectively, in colloidal drug delivery systems (for example,liposomes, albumin microspheres, microemulsions, nano-particles andnanocapsules) or in macroemulsions. Such techniques are disclosed inRemington's Pharmaceutical Sciences 16th edition, Osol, A. Ed. (1980).

The formulations to be used for in vivo administration are typicallysterile. This is readily accomplished by filtration through sterilefiltration membranes.

Sustained-release preparations may be prepared. Suitable examples ofsustained-release preparations include semipermeable matrices of solidhydrophobic polymers containing the anti-CD22 antibody, which matricesare in the form of shaped articles, e.g., films, or microcapsule.Examples of sustained-release matrices include polyesters, hydrogels(for example, poly(2-hydroxyethyl-methacrylate), or poly(vinylalcohol)),polylactides (U.S. Pat. No. 3,773,919), copolymers of L-glutamic acidand γ-ethyl-L-glutamate, non-degradable ethylene-vinyl acetate,degradable lactic acid-glycolic acid copolymers such as the LUPRONDEPOT™ (injectable microspheres composed of lactic acid-glycolic acidcopolymer and leuprolide acetate), and poly-D-(−)-3-hydroxybutyric acid.While polymers such as ethylene-vinyl acetate and lactic acid-glycolicacid enable release of molecules for over 100 days, certain hydrogelsrelease proteins for shorter time periods. When encapsulated antibodiesremain in the body for a long time, they may denature or aggregate as aresult of exposure to moisture at 37° C., resulting in a loss ofbiological activity and possible changes in immunogenicity. Rationalstrategies can be devised for stabilization depending on the mechanisminvolved. For example, if the aggregation mechanism is discovered to beintermolecular S—S bond formation through thio-disulfide interchange,stabilization may be achieved by modifying sulfhydryl residues,lyophilizing from acidic solutions, controlling moisture content, usingappropriate additives, and developing specific polymer matrixcompositions. In certain embodiments, the pharmaceutically acceptablecarriers used in the compositions of the invention do not affect humanADCC or CDC.

The anti-CD22 antibody compositions disclosed herein may also beformulated as immunoliposomes. A “liposome” is a small vesicle composedof various types of lipids, phospholipids and/or surfactant which isuseful for delivery of a drug (such as the anti-CD22 antibodiesdisclosed herein) to a human. The components of the liposome arecommonly arranged in a bilayer formation, similar to the lipidarrangement of biological membranes. Liposomes containing the antibodiesof the invention are prepared by methods known in the art, such asdescribed in Epstein et al., Proc. Natl. Acad. Sci. USA, 82:3688 (1985);Hwang et al., Proc. Natl. Acad. Sci. USA, 77:4030 (1980); and U.S. Pat.Nos. 4,485,045 and 4,544,545. Liposomes with enhanced circulation timeare disclosed in U.S. Pat. No. 5,013,556. Particularly useful liposomescan be generated by the reverse phase evaporation method with a lipidcomposition comprising phosphatidylcholine, cholesterol andPEG-derivatized phosphatidylethanolamine (PEG-PE). Liposomes areextruded through filters of defined pore size to yield liposomes withthe desired diameter. The antibody of the present invention can beconjugated to the liposomes as described in Martin et al., J. Biol.Chem., 257:286-288 (1982) via a disulfide interchange reaction. Atherapeutic agent can also be contained within the liposome. See,Gabizon et al., J. National Cancer Inst., (19)1484 (1989).

Some of the preferred pharmaceutical formulations include, but are notlimited to:

(a) a sterile, preservative-free liquid concentrate for intravenous(i.v.) administration of anti-CD22 antibody, supplied at a concentrationof 10 mg/ml in either 100 mg (10 mL) or 500 mg (50 mL) single-use vials.The product can be formulated for i.v. administration using sodiumchloride, sodium citrate dihydrate, polysorbate and sterile water forinjection. For example, the product can be formulated in 9.0 mg/mLsodium chloride, 7.35 mg/mL sodium citrate dihydrate, 0.7 mg/mLpolysorbate 80, and sterile water for injection. The pH is adjusted to6.5.

(b) A sterile, lyophilized powder in single-use glass vials forsubcutaneous (s.c.) injection. The product can be formulated withsucrose, L-histidine hydrochloride monohydrate, L-histidine andpolysorbate 20. For example, each single-use vial can contain 150 mganti-CD22 antibody, 123.2 mg sucrose, 6.8 mg L-histidine hydrochloridemonohydrate, 4.3 mg L-histidine, and 3 mg polysorbate 20. Reconstitutionof the single-use vial with 1.3 ml sterile water for injection yieldsapproximately 1.5 ml solution to deliver 125 mg per 1.25 ml (100 mg/ml)of antibody.

(c) A sterile, preservative-free lyophilized powder for intravenous(i.v.) administration. The product can be formulated with α-trehalosedihydrate, L-histidine HCl, histidine and polysorbate 20 USP. Forexample, each vial can contain 440 mg anti-CD22 antibody, 400 mgα,α-trehalose dihydrate, 9.9 mg L-histidine HCl, 6.4 mg L-histidine, and1.8 mg polysorbate 20, USP. Reconstitution with 20 ml of bacteriostaticwater for injection (BWFI), USP, containing 1.1% benzyl alcohol as apreservative, yields a multi-dose solution containing 21 mg/ml antibodyat a pH of approximately 6.

(d) A sterile, lyophilized powder for intravenous infusion in which theanti-CD22 antibody is formulated with sucrose, polysorbate, monobasicsodium phosphate monohydrate, and dibasic sodium phosphate dihydrate.For example, each single-use vial can contain 100 mg antibody, 500 mgsucrose, 0.5 mg polysorbate 80, 2.2 mg monobasic sodium phosphatemonohydrate, and 6.1 mg dibasic sodium phosphate dihydrate. Nopreservatives are present. Following reconstitution with 10 ml sterilewater for injection, USP, the resulting pH is approximately 7.2.

(e) A sterile, preservative-free solution for subcutaneousadministration supplied in a single-use, 1 ml pre-filled syringe. Theproduct can be formulated with sodium chloride, monobasic sodiumphosphate dihydrate, dibasic sodium phosphate dihydrate, sodium citrate,citric acid monohydrate, mannitol, polysorbate 80 and water forinjection, USP. Sodium hydroxide may be added to adjust pH to about 5.2.

For example, each syringe can be formulated to deliver 0.8 ml (40 mg) ofdrug product. Each 0.8 ml contains 40 mg anti-CD22 antibody, 4.93 mgsodium chloride, 0.69 mg monobasic sodium phosphate dihydrate, 1.22 mgdibasic sodium phosphate dihydrate, 0.24 mg sodium citrate, 1.04 citricacid monohydrate, 9.6 mg mannitol, 0.8 mg polysorbate 80 and water forinjection, USP.

(f) A sterile, preservative-free, lyophilized powder contained in asingle-use vial that is reconstituted with sterile water for injection(SWFI), USP, and administered as a subcutaneous (s.c.) injection. Theproduct can be formulated with sucrose, histidine hydrochloridemonohydrate, L-histidine, and polysorbate. For example, a 75 mg vial cancontain 129.6 mg or 112.5 mg of the anti-CD22 antibody, 93.1 mg sucrose,1.8 mg L-histidine hydrochloride monohydrate, 1.2 mg L-histidine, and0.3 mg polysorbate 20, and is designed to deliver 75 mg of the antibodyin 0.6 ml after reconstitution with 0.9 ml SWFI, USP. A 150 mg vial cancontain 202.5 mg or 175 mg anti-CD22 antibody, 145.5 mg sucrose, 2.8 mgL-histidine hydrochloride monohydrate, 1.8 mg L-histidine, and 0.5 mgpolysorbate 20, and is designed to deliver 150 mg of the antibody in 1.2ml after reconstitution with 1.4 ml SWFI, USP.

(g) A sterile, lyophilized product for reconstitution with sterile waterfor injection. The product can be formulated as single-use vials forintramuscular (IM) injection using mannitol, histidine and glycine. Forexample, each single-use vial can contain 100 mg anti-CD22 antibody,67.5 mg of mannitol, 8.7 mg histidine and 0.3 mg glycine, and isdesigned to deliver 100 mg antibody in 1.0 ml when reconstituted with1.0 ml sterile water for injection. Alternatively, each single-use vialcan contain 50 mg anti-CD22 antibody, 40.5 mg mannitol, 5.2 mg histidineand 0.2 mg glycine, and is designed to deliver 50 mg of antibody whenreconstituted with 0.6 ml sterile water for injection.

(h) A sterile, preservative-free solution for intramuscular (IM)injection, supplied at a concentration of 100 mg/ml. The product can beformulated in single-use vials with histidine, glycine, and sterilewater for injection. For example, each single-use vial can be formulatedwith 100 mg antibody, 4.7 mg histidine, and 0.1 mg glycine in a volumeof 1.2 ml designed to deliver 100 mg of antibody in 1 ml. Alternatively,each single-use vial can be formulated with 50 mg antibody, 2.7 mghistidine and 0.08 mg glycine in a volume of 0.7 ml or 0.5 ml designedto deliver 50 mg of antibody in 0.5 ml.

In certain embodiments, the pharmaceutical composition of the inventionis stable at 4° C. In certain embodiments, the pharmaceuticalcomposition of the invention is stable at room temperature.

5.20.2. Antibody Half-Life

In certain embodiments, the half-life of an anti-CD22 antibody of thecompositions and methods of the invention is at least about 4 to 7 days.In certain embodiments, the mean half-life of the anti-CD22 antibody ofthe compositions and methods of the invention is at least about 2 to 5days, 3 to 6 days, 4 to 7 days, 5 to 8 days, 6 to 9 days, 7 to 10 days,8 to 11 days, 8 to 12, 9 to 13, 10 to 14, 11 to 15, 12 to 16, 13 to 17,14 to 18, 15 to 19, or 16 to 20 days. In other embodiments, the meanhalf-life of the anti-CD22 antibody of the compositions and methods ofthe invention is at least about 17 to 21 days, 18 to 22 days, 19 to 23days, 20 to 24 days, 21 to 25, days, 22 to 26 days, 23 to 27 days, 24 to28 days, 25 to 29 days, or 26 to 30 days. In still further embodimentsthe half-life of an anti-CD22 antibody of the compositions and methodsof the invention can be up to about 50 days. In certain embodiments, thehalf-lives of the antibodies of the compositions and methods of theinvention can be prolonged by methods known in the art. Suchprolongation can in turn reduce the amount and/or frequency of dosing ofthe antibody compositions of the invention. Antibodies with improved invivo half-lives and methods for preparing them are disclosed in U.S.Pat. No. 6,277,375; and International Publication Nos. WO 98/23289 andWO 97/3461.

The serum circulation of the anti-CD22 antibodies of the invention invivo may also be prolonged by attaching inert polymer molecules such ashigh molecular weight polyethyleneglycol (PEG) to the antibodies with orwithout a multifunctional linker either through site-specificconjugation of the PEG to the N- or C-terminus of the antibodies or viaepsilon-amino groups present on lysyl residues. Linear or branchedpolymer derivatization that results in minimal loss of biologicalactivity will be used. The degree of conjugation can be closelymonitored by SDS-PAGE and mass spectrometry to ensure proper conjugationof PEG molecules to the antibodies. Unreacted PEG can be separated fromantibody-PEG conjugates by size-exclusion or by ion-exchangechromatography. PEG-derivatized antibodies can be tested for bindingactivity as well as for in vivo efficacy using methods known to those ofskill in the art, for example, by immunoassays described herein.

Further, the antibodies of the compositions and methods of the inventioncan be conjugated to albumin in order to make the antibody more stablein vivo or have a longer half-life in vivo. The techniques are wellknown in the art, see, e.g., International Publication Nos. WO 93/15199,WO 93/15200, and WO 01/77137; and European Patent No. EP 413, 622, allof which are incorporated herein by reference.

5.20.3. Administration and Dosing

Administration of the compositions of the invention to a human patientcan be by any route, including but not limited to intravenous,intradermal, transdermal, subcutaneous, intramuscular, inhalation (e.g.,via an aerosol), buccal (e.g., sub-lingual), topical (i.e., both skinand mucosal surfaces, including airway surfaces), intrathecal,intraarticular, intraplural, intracerebral, intra-arterial,intraperitoneal, oral, intralymphatic, intranasal, rectal or vaginaladministration, by perfusion through a regional catheter, or by directintralesional injection. In a preferred embodiment, the compositions ofthe invention are administered by intravenous push or intravenousinfusion given over defined period (e.g., 0.5 to 2 hours). Thecompositions of the invention can be delivered by peristaltic means orin the form of a depot, although the most suitable route in any givencase will depend, as is well known in the art, on such factors as thespecies, age, gender and overall condition of the subject, the natureand severity of the condition being treated and/or on the nature of theparticular composition (i.e., dosage, formulation) that is beingadministered. In particular embodiments, the route of administration isvia bolus or continuous infusion over a period of time, once or twice aweek. In other particular embodiments, the route of administration is bysubcutaneous injection, optionally once or twice weekly. In oneembodiment, the compositions, and/or methods of the invention areadministered on an outpatient basis.

In certain embodiments, the dose of a composition comprising anti-CD22antibody is measured in units of mg/kg of patient body weight. In otherembodiments, the dose of a composition comprising anti-CD22 antibody ismeasured in units of mg/kg of patient lean body weight (i.e., bodyweight minus body fat content). In yet other embodiments, the dose of acomposition comprising anti-CD22 antibody is measured in units of mg/m²of patient body surface area. In yet other embodiments, the dose of acomposition comprising anti-CD22 antibody is measured in units of mg perdose administered to a patient. Any measurement of dose can be used inconjunction with the compositions and methods of the invention anddosage units can be converted by means standard in the art.

Those skilled in the art will appreciate that dosages can be selectedbased on a number of factors including the age, sex, species andcondition of the subject (e.g., stage of B cell malignancy), the desireddegree of cellular depletion, the disease to be treated and/or theparticular antibody or antigen-binding fragment being used and can bedetermined by one of skill in the art. For example, effective amounts ofthe compositions of the invention may be extrapolated from dose-responsecurves derived in vitro test systems or from animal model (e.g., thecotton rat or monkey) test systems. Models and methods for evaluation ofthe effects of antibodies are known in the art (Wooldridge et al.,Blood, 89(8): 2994-2998 (1997)), incorporated by reference herein in itsentirety). In certain embodiments, for particular B cell malignancies,therapeutic regimens standard in the art for antibody therapy can beused with the compositions and methods of the invention.

Examples of dosing regimens that can be used in the methods of theinvention include, but are not limited to, daily, three times weekly(intermittent), weekly, or every 14 days. In certain embodiments, dosingregimens include, but are not limited to, monthly dosing or dosing every6-8 weeks.

Those skilled in the art will appreciate that dosages are generallyhigher and/or frequency of administration greater for initial treatmentas compared with maintenance regimens.

In embodiments of the invention, the anti-CD22 antibodies bind to Bcells and, thus, can result in more efficient (i.e., at lower dosage)depletion of B cells (as described herein). Higher degrees of bindingmay be achieved where the density of human CD22 on the surface of apatient's B cells is high. In exemplary embodiments, dosages of theantibody (optionally in a pharmaceutically acceptable carrier as part ofa pharmaceutical composition) are at least about 0.0005, 0.001, 0.05,0.075, 0.1, 0.25, 0.375, 0.5, 1, 2.5, 5, 10, 20, 37.5, or 50 mg/m²and/or less than about 500, 475, 450, 425, 400, 375, 350, 325, 300, 275,250, 225, 200, 175, 150, 125, 100, 75, 60, 50, 37.5, 20, 15, 10, 5, 2.5,1, 0.5, 0.375, 0.1, 0.075 or 0.01 mg/m². In certain embodiments, thedosage is between about 0.0005 to about 200 mg/m², between about 0.001and 150 mg/m², between about 0.075 and 125 mg/m², between about 0.375and 100 mg/m², between about 2.5 and 75 mg/m², between about 10 and 75mg/m², and between about 20 and 50 mg/m². In related embodiments, thedosage of anti-CD22 antibody used is at least about 0.1, 0.2, 0.3, 0.4,0.5, 0.6, 0.7, 0.8, 0.9, 1, 1.5, 2, 2.5, 3, 3.5, 4, 4.5, 5, 5.5, 6, 6.5,7, 7.5, 8, 8.5, 9, 9.5, 10, 10.5, 11, 11.5, 12, 12.5, 13, 13.5, 14,14.5, 15, 15.5, 16, 16.5, 17, 17.5, 18, 18.5, 19, 19.5, 20, 20.5 mg/kgof body weight of a patient. In certain embodiments, the dose of nakedanti-CD22 antibody used is at least about 1 to 10, 5 to 15, 10 to 20, or15 to 25 mg/kg of body weight of a patient. In certain embodiments, thedose of anti-CD22 antibody used is at least about 1 to 20, 3 to 15, or 5to 10 mg/kg of body weight of a patient. In preferred embodiments, thedose of anti-CD22 antibody used is at least about 5, 6, 7, 8, 9, or 10mg/kg of body weight of a patient. In certain embodiments, a singledosage unit of the antibody (optionally in a pharmaceutically acceptablecarrier as part of a pharmaceutical composition) can be at least about0.5, 1, 2, 4, 6, 8, 10, 12, 14, 16, 18, 20, 22, 24, 26, 28, 30, 32, 34,36, 38, 40, 42, 44, 46, 48, 50, 52, 54, 56, 58, 60, 62, 64, 66, 68, 70,72, 74, 76, 78, 80, 82, 84, 86, 88, 90, 92, 94, 96, 98, 100, 102, 104,106, 108, 110, 112, 114, 116, 118, 120, 122, 124, 126, 128, 130, 132,134, 136, 138, 140, 142, 144, 146, 148, 150, 152, 154, 156, 158, 160,162, 164, 166, 168, 170, 172, 174, 176, 178, 180, 182, 184, 186, 188,190, 192, 194, 196, 198, 200, 204, 206, 208, 210, 212, 214, 216, 218,220, 222, 224, 226, 228, 230, 232, 234, 236, 238, 240, 242, 244, 246,248, or 250 micrograms/m². In other embodiments, dose is up to 1 g persingle dosage unit.

All of the above doses are exemplary and can be used in conjunction withthe compositions and methods of the invention, however where ananti-CD22 antibody is used in conjunction with a toxin orradiotherapeutic agent the lower doses described above are preferred. Incertain embodiments, where the patient has low levels of CD22 density,the lower doses described above are preferred.

In certain embodiments of the invention where chimeric anti-CD22antibodies are used, the dose or amount of the chimeric antibody isgreater than about 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, or 16mg/kg of patient body weight. In other embodiments of the inventionwhere chimeric anti-CD22 antibodies are used, the dose or amount of thechimeric antibody is less than about 1, 0.9, 0.8, 0.7, 0.6, 0.5, 0.4,0.3, 0.2, or 0.1 mg/kg of patient body weight.

In some embodiments of the methods of this invention, antibodies and/orcompositions of this invention can be administered at a dose lower thanabout 375 mg/m²; at a dose lower than about 37.5 mg/m²; at a dose lowerthan about 0.375 mg/m²; and/or at a dose between about 0.075 mg/m² andabout 125 mg/m². In preferred embodiments of the methods of theinvention, dosage regimens comprise low doses, administered at repeatedintervals. For example, in one embodiment, the compositions of theinvention can be administered at a dose lower than about 375 mg/m² atintervals of approximately every 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 15, 20,25, 30, 35, 40, 45, 50, 60, 70, 80, 90, 100, 125, 150, 175, or 200 days.

The specified dosage can result in B cell depletion in the human treatedusing the compositions and methods of the invention for a period of atleast about 1, 2, 3, 5, 7, 10, 14, 20, 30, 45, 60, 75, 90, 120, 150 or180 days or longer. In certain embodiments, pre-B cells (not expressingsurface immunoglobulin) are depleted. In certain embodiments, mature Bcells (expressing surface immunoglobulin) are depleted. In otherembodiments, all non-malignant types of B cells can exhibit depletion.Any of these types of B cells can be used to measure B cell depletion. Bcell depletion can be measured in bodily fluids such as blood serum, orin tissues such as bone marrow. In preferred embodiments of the methodsof the invention, B cells are depleted by at least 30%, 40%, 50%, 60%,70%, 80%, 90%, or 100% in comparison to B cell levels in the patientbeing treated before use of the compositions and methods of theinvention. In preferred embodiments of the methods of the invention, Bcells are depleted by at least 30%, 40%, 50%, 60%, 70%, 80%, 90%, or100% in comparison to typical standard B cell levels for humans. Inrelated embodiments, the typical standard B cell levels for humans aredetermined using patients comparable to the patient being treated withrespect to age, sex, weight, and other factors.

In certain embodiments of the invention, a dosage of about 125 mg/m² orless of an antibody or antigen-binding fragment results in B celldepletion for a period of at least about 7, 14, 21, 30, 45, 60, 90, 120,150, or 200 days. In another representative embodiment, a dosage ofabout 37.5 mg/m² or less depletes B cells for a period of at least about7, 14, 21, 30, 45, 60, 90, 120, 150, or 200 days. In still otherembodiments, a dosage of about 0.375 mg/m² or less results in depletionof B cells for at least about 7, 14, 21, 30, 45 or 60 days. In anotherembodiment, a dosage of about 0.075 mg/m² or less results in depletionof B cells for a period of at least about 7, 14, 21, 30, 45, 60, 90,120, 150, or 200 days. In yet other embodiments, a dosage of about 0.01mg/m², 0.005 mg/m² or even 0.001 mg/m² or less results in depletion of Bcells for at least about 3, 5, 7, 10, 14, 21, 30, 45, 60, 90, 120, 150,or 200 days. According to these embodiments, the dosage can beadministered by any suitable route, but is optionally administered by asubcutaneous route.

As another aspect, the invention provides the discovery that B celldepletion and/or treatment of B cell disorders can be achieved at lowerdosages of antibody or antibody fragments than employed in currentlyavailable methods. Thus, in another embodiment, the invention provides amethod of depleting B cells and/or treating a B cell disorder,comprising administering to a human, an effective amount of an antibodythat specifically binds to CD22, wherein a dosage of about 500, 475,450, 425, 400, 375, 350, 325, 300, 275, 250, 225, 200, 175, 150, 125,100, 75, 60, 50, 37.5, 20, 10, 5, 2.5, 1, 0.5, 0.375, 0.25, 0.1, 0.075,0.05, 0.001, 0.0005 mg/m² or less results in a depletion of B cells(circulating and/or tissue B cells) of 25%, 35%, 50%, 60%, 75%, 80%,85%, 90%, 95%, 98% or more for a period at least about 3, 5, 7, 10, 14,21, 30, 45, 60, 75, 90, 120, 150, 180, or 200 days or longer. Inrepresentative embodiments, a dosage of about 125 mg/m² or 75 mg/m² orless results in at least about 50%, 75%, 85% or 90% depletion of B cellsfor at least about 7, 14, 21, 30, 60, 75, 90, 120, 150 or 180 days. Inother embodiments, a dosage of about 50, 37.5 or 10 mg/m² results in atleast about a 50%, 75%, 85% or 90% depletion of B cells for at leastabout 7, 14, 21, 30, 60, 75, 90, 120 or 180 days. In still otherembodiments, a dosage of about 0.375 or 0.1 mg/m² results in at leastabout a 50%, 75%, 85% or 90% depletion of B cells for at least about 7,14, 21, 30, 60, 75 or 90 days. In further embodiments, a dosage of about0.075, 0.01, 0.001, or 0.0005 mg/m² results in at least about a 50%,75%, 85% or 90% depletion of B cells for at least about 7, 14, 21, 30 or60 days.

In certain embodiments of the invention, the dose can be escalated orreduced to maintain a constant dose in the blood or in a tissue, suchas, but not limited to, bone marrow. In related embodiments, the dose isescalated or reduced by about 2%, 5%, 8%, 10%, 15%, 20%, 30%, 40%, 50%,60%, 70%, 80%, 90%, and 95% in order to maintain a desired level of theantibody of the compositions and methods of the invention.

In certain embodiments, the dosage can be adjusted and/or the infusionrate can be reduced based on patient's immunogenic response to thecompositions and methods of the invention.

According to one aspect of the methods of the invention, a loading doseof the anti-CD22 antibody and/or composition of the invention can beadministered first followed by a maintenance dose until the B cellmalignancy being treated progresses or followed by a defined treatmentcourse (e.g., CAMPATH™, MYLOTARG™, or RITUXAN™, the latter of whichallow patients to be treated for a defined number of doses that hasincreased as additional data have been generated).

According to another aspect of the methods of the invention, a patientmay be pretreated with the compositions and methods of the invention todetect, minimize immunogenic response, or minimize adverse effects ofthe compositions and methods of the invention.

5.20.4. Toxicity Testing

The tolerance, toxicity and/or efficacy of the compositions and/ortreatment regimens of the present invention can be determined bystandard pharmaceutical procedures in cell cultures or experimentalanimals, e.g., for determining the LD50 (the dose lethal to 50% of thepopulation), the ED50 (the dose therapeutically effective in 50% of thepopulation), and IC50 (the dose effective to achieve a 50% inhibition).In a preferred embodiment, the dose is a dose effective to achieve atleast a 60%, 70%, 80%, 90%, 95%, or 99% depletion of circulating B cellsor circulating immunoglobulin, or both. The dose ratio between toxic andtherapeutic effects is the therapeutic index and it can be expressed asthe ratio LD50/ED50. Therapies that exhibit large therapeutic indicesare preferred. While therapies that exhibit toxic side effects may beused, care should be taken to design a delivery system that targets suchagents to CD22-expressing cells in order to minimize potential damage toCD22 negative cells and, thereby, reduce side effects.

Data obtained from the cell culture assays and animal studies can beused in formulating a range of dosages of the compositions and/ortreatment regimens for use in humans. The dosage of such agents liespreferably within a range of circulating concentrations that include theED50 with little or no toxicity. The dosage may vary within this rangedepending upon the dosage form employed and the route of administrationutilized. For any therapy used in the methods of the invention, thetherapeutically effective dose can be estimated by appropriate animalmodels. Depending on the species of the animal model, the dose is scaledfor human use according to art-accepted formulas, for example, asprovided by Freireich et al., Quantitative comparison of toxicity ofanticancer agents in mouse, rat, monkey, dog, and human, CancerChemotherapy Reports, NCI 1966 40:219-244. Data obtained from cellculture assays can be useful for predicting potential toxicity. Animalstudies can be used to formulate a specific dose to achieve acirculating plasma concentration range that includes the IC50 (i.e., theconcentration of the test compound that achieves a half-maximalinhibition of symptoms) as determined in cell culture. Such informationcan be used to more accurately determine useful doses in humans. Plasmadrug levels may be measured, for example, by high performance liquidchromatography, ELISA, or by cell based assays.

5.21. Patient Diagnosis, Staging and Therapeutic Regimens Oncology

According to certain aspects of the invention, the treatment regimen anddose used with the compositions and methods of the invention is chosenbased on a number of factors including, but not limited to, the stage ofthe B cell disease or disorder being treated. Appropriate treatmentregimens can be determined by one of skill in the art for particularstages of a B cell disease or disorder in a patient or patientpopulation. Dose response curves can be generated using standardprotocols in the art in order to determine the effective amount of thecompositions of the invention for treating patients having differentstages of a B cell disease or disorder. In general, patients having moreadvanced stages of a B cell disease or disorder will require higherdoses and/or more frequent doses which may be administered over longerperiods of time in comparison to patients having an early stage B celldisease or disorder.

The anti-CD22 antibodies, compositions and methods of the invention canbe practiced to treat B cell diseases, including B cell malignancies.The term “B cell malignancy” includes any malignancy that is derivedfrom a cell of the B cell lineage. Exemplary B cell malignanciesinclude, but are not limited to: B cell subtype non-Hodgkin's lymphoma(NHL) including low grade/follicular NHL, small lymphocytic (SL) NHL,intermediate grade/follicular NHL, intermediate grade diffuse NHL, highgrade immunoblastic NHL, high grade lymphoblastic NHL, high grade smallnon-cleaved cell NHL; mantle-cell lymphoma, and bulky disease NHL;Burkitt's lymphoma; multiple myeloma; pre-B acute lymphoblastic leukemiaand other malignancies that derive from early B cell precursors; commonacute lymphocytic leukemia (ALL); chronic lymphocytic leukemia (CLL)including immunoglobulin-mutated CLL and immunoglobulin-unmutated CLL;hairy cell leukemia; Null-acute lymphoblastic leukemia; Waldenstrom'sMacroglobulinemia; diffuse large B cell lymphoma (DLBCL) includinggerminal center B cell-like (GCB) DLBCL, activated B cell-like (ABC)DLBCL, and type 3 DLBCL; pro-lymphocytic leukemia; light chain disease;plasmacytoma; osteosclerotic myeloma; plasma cell leukemia; monoclonalgammopathy of undetermined significance (MGUS); smoldering multiplemyeloma (SMM); indolent multiple myeloma (IMM); Hodgkin's lymphomaincluding classical and nodular lymphocyte pre-dominant type;lymphoplasmacytic lymphoma (LPL); and marginal-zone lymphoma includinggastric mucosal-associated lymphoid tissue (MALT) lymphoma.

In one aspect of the invention, the antibodies and compositions of theinvention can deplete mature B cells. Thus, as another aspect, theinvention can be employed to treat mature B cell malignancies (i.e.,express Ig on the cell surface) including but not limited to follicularlymphoma, mantle-cell lymphoma, Burkitt's lymphoma, multiple myeloma,diffuse large B-cell lymphoma (DLBCL) including germinal center Bcell-like (GCB) DLBCL, activated B cell-like (ABC) DLBCL, and type 3DLBCL, Hodgkin's lymphoma including classical and nodular lymphocytepre-dominant type, lymphoplasmacytic lymphoma (LPL), marginal-zonelymphoma including gastric mucosal-associated lymphoid tissue (MALT)lymphoma, and chronic lymphocytic leukemia (CLL) includingimmunoglobulin-mutated CLL and immunoglobulin-unmutated CLL.

Further, CD22 is expressed earlier in B cell development than, forexample, CD20, and is therefore particularly suited for treating pre-Bcell and immature B cell malignancies (i.e., do not express Ig on thecell surface), for example, in the bone marrow. Illustrative pre-B celland immature B cell malignancies include, but are not limited to, acutelymphoblastic leukemia.

In other particular embodiments, the invention can be practiced to treatextranodal tumors.

5.21.1. Diagnosis and Staging of B Cell Malignancies

The progression of cancer, such as a B cell disease or disorder capableof tumor formation (e.g., non-Hodgkin lymphoma, diffuse large B celllymphoma, follicular lymphoma, and Burkitt's lymphoma) is typicallycharacterized by the degree to which the cancer has spread through thebody and is often broken into the following four stages which areprognostic of outcome. Stage I: The cancer is localized to a particulartissue and has not spread to the lymph nodes. Stage II: The cancer hasspread to the nearby lymph nodes, i.e., metastasis. Stage III: Thecancer is found in the lymph nodes in regions of the body away from thetissue of origin and may comprise a mass or multiple tumors as opposedto one. Stage IV: The cancer has spread to a distant part of the body.The stage of a cancer can be determined by clinical observations andtesting methods that are well known to those of skill in the art. Thestages of cancer described above are traditionally used in conjunctionwith clinical diagnosis of cancers characterized by tumor formation, andcan be used in conjunction with the compositions and methods of thepresent invention to treat B cell diseases and disorders. Typicallyearly stage disease means that the disease remains localized to aportion of a patient's body or has not metastasized.

With respect to non-tumor forming B cell diseases and disorders such as,but not limited to, multiple myeloma, the criteria for determining thestage of disease differs. The Durie-Salmon Staging System has beenwidely used. In this staging system, clinical stage of disease (stage I,II, or III) is based on several measurements, including levels of Mprotein, the number of lytic bone lesions, hemoglobin values, and serumcalcium levels. Stages are further divided according to renal (kidney)function (classified as A or B). According to the Durie-Salmon StagingSystem Stage I (low cell mass) is characterized by all of the following:Hemoglobin value>10 g/dL; Serum calcium value normal or ≦12 mg/dL; Bonex-ray, normal bone structure (scale 0) or solitary bone plasmacytomaonly; and Low M-component production rate: IgG value<5 g/dL, IgA value<3g/d, Bence Jones protein<4 g/24 h. Stage I patients typically have norelated organ or tissue impairment or symptoms. Stage II (intermediatecell mass) is characterized by fitting neither stage I nor stage III.Stage III (high cell mass) is characterized by one or more of thefollowing: Hemoglobin value<8.5 g/dL; Serum calcium value>12 mg/dL;Advanced lytic bone lesions (scale 3); High M-component production rate:IgG value>7 g/dL, IgA value>5 g/dL, Bence Jones protein>12 g/24 hSubclassification (either A or B), where A is Relatively normal renalfunction (serum creatinine value<2.0 mg/dL) and B is Abnormal renalfunction (serum creatinine value≧2.0 mg/dL).

Another staging system for myeloma is the International Staging System(ISS) for myeloma. This system can more effectively discriminate betweenstaging groups and is based on easily measured serum levels of beta2-microglobulin (β2-M) and albumin. According to the ISS for myeloma,Stage I is characterized by β2-M<3.5 and Albumin≧3.5, Stage II ischaracterized by β2-M<3.5 and albumin<3.5 or β2-M 3.5-5.5, and Stage IIIis characterized by β2-M>5.5 (Multiple Myeloma Research Foundation, NewCanaan, Conn.).

The stage of a B cell malignancy in a patient is a clinicaldetermination. As indicated above, with respect to solid tumors, thespread, location, and number of tumors are the primary factors in theclinical determination of stage. Determination of stage in patients withnon-tumor forming B cell malignancies can be more complex requiringserum level measurements as described above.

The descriptions of stages of B cell diseases and disorders above arenot limiting. Other characteristics known in the art for the diagnosisof B cell diseases and disorders can be used as criteria for patients todetermine stages of B cell diseases or disorders.

5.21.2. Clinical Criteria for Diagnosing B Cell Malignancies

Diagnostic criteria for different B cell malignancies are known in theart. Historically, diagnosis is typically based on a combination ofmicroscopic appearance and immunophenotype. More recently, moleculartechniques such as gene-expression profiling have been applied todevelop molecular definitions of B cell malignancies (see, e.g., Shafferet al., Nature 2:920-932 (2002)). Exemplary methods for clinicaldiagnosis of particular B cell malignancies are provided below. Othersuitable methods will be apparent to those skilled in the art.

5.21.2.1. Follicular NHL

In general, most NHL (with the exception of mantle-cell lymphoma) havehighly mutated immunoglobulin genes that appear to be the result ofsomatic hypermutation (SHM). The most common genetic abnormalities inNHL are translocations and mutations of the BCL6 gene.

Follicular NHL is often an indolent B cell lymphoma with a folliculargrowth pattern. It is the second most common lymphoma in the UnitedStates and Western Europe. The median age at which this disease presentsis 60 years and there is a slight female predominance. Painlesslymphadenopathy is the most common symptom. Tests often indicateinvolvement of the blood marrow and sometimes the peripheral blood.Follicular NHL is divided into cytologic grades based on the proportionof large cells in the follicle with the grades forming a continuum fromfollicular small cleaved-cell to large-cell predominance. (See, S.Freedman, et al., Follicular Lymphoma, pp. 367-388, In Non-Hodgkin'sLymphomas, P. Mauch et al., eds., Lippincott Williams & Wilkins,Philadelphia, Pa. (2004); T. Lister et al., Follicular Lymphoma, pp.309-324, In Malignant Lymphoma, B. Hancock et al., eds., OxfordUniversity Press, New York, N.Y. (2000)).

Most follicular NHL is characterized by a translocation betweenchromosomes 14 and 18 resulting in overexpression of BCL2. FollicularNHL is also characterized by both SHM and ongoing SHM and a geneexpression profile similar to germinal center (GC) B cells (see, e.g.,Shaffer et al., Nature 2:920-932 (2002)), which are the putative cellsof origin for this malignancy. Heavy- and light chain rearrangements aretypical. The tumor cells of this disease express monoclonal surfaceimmunoglobulin with most expressing IgM. Nearly all follicular NHL tumorcells express the antigens CD22, CD20, CD79a, CD21, CD35 and CD10 butlack expression of CD5 and CD43. Paratrabecular infiltration with smallcleaved cells is observed in the bone marrow. (See, S. Freedman et al.,Follicular Lymphoma, pp. 367-388, In Non-Hodgkin's Lymphomas, P. Mauchet al., eds., Lippincott Williams & Wilkins, Philadelphia, Pa. (2004);T. Lister et al., Follicular Lymphoma, pp. 309-324, In MalignantLymphoma, B. Hancock et al., eds., Oxford University Press, New York,N.Y. (2000)).

Diagnosis of follicular NHL generally relies on biopsy of an excisednode in order to evaluate tissue architecture and cytological features.Fine-needle aspirations are usually not adequate since this procedure isless likely to provide tissue that can be evaluated and it fails toprovide enough tissue for additional tests. Bilateral bone marrowbiopsies are also indicated since involvement can be patchy. Additionaldiagnostic procedures include chest x-rays, chest, abdomen, neck andpelvis computed tomography (CT) scans, complete blood count, andchemistry profile. Flow cytometry and immunohistochemistry can be usedto distinguish between follicular NHL and other mature B cell lymphomas.(See, S. Freedman et al., Follicular Lymphoma, pp. 367-388, InNon-Hodgkin's Lymphomas, P. Mauch et al., eds., Lippincott Williams &Wilkins, Philadelphia, Pa. (2004); T. Lister et al., FollicularLymphoma, pp. 309-324, In Malignant Lymphoma, B. Hancock et al., eds.,Oxford University Press, New York, N.Y. (2000)).

5.21.2.2. Mantle-Cell Lymphoma

Mantle-cell lymphoma localizes to the mantle region of secondaryfollicles and is characterized by a nodular and/or diffuse growthpattern. Mantle-cell lymphoma patients have median age of 60-65 yearswith the disease affecting predominantly males. For diagnostic purposes,the usual presenting feature is a generalized lymphadenopathy.Additionally, the spleen is often enlarged. This B cell lymphoma isassociated with a t(11;14) between the IgH locus and cyclin D1 gene,which results in overexpression of cyclin D1. More than 50% of casesshow additional chromosomal abnormalities. Mantle-cell lymphoma istypically not characterized by SHM. (See, W. Hiddemann et al., MantleCell Lymphoma, pp. 461-476, In Non-Hodgkin's Lymphomas, P. Mauch et al.,eds., Lippincott Williams & Wilkins, Philadelphia, Pa. (2004); D.Weisenburger et al., Mantle Cell Lymphoma, pp. 28-41, In MalignantLymphoma, B. Hancock et al., eds., Oxford University Press, New York,N.Y. (2000)).

Immunophenotyping (flow cytometry or frozen section)immunohistochemistry of mantle cell lymphoma cells shows them to nearlyalways be monoclonal, bearing surface IgM. Mantle cell lymphoma cellshave also been noted to bear surface IgD. The cells express the antigensCD22, CD20, CD22 and CD24, but not CD23. They also express surfaceantigens CD5 but not for CD10, distinguishing them from true folliclecenter-cell lymphomas which are almost always CD5 negative. Frequently,extranodal involvement is found including bone marrow infiltration andtumors of the liver and gastrointestinal tract. Mild anemia and leukemicexpression is not uncommon with mantle-cell lymphoma. (See, A. Lal etal., Role of Fine Needle Aspiration in Lymphoma, pp. 181-220, In W. Finnet al., eds., Hematopathology in Oncology, Kluwer Academic Publishers,Norwell, Mass. (2004); W. Hiddemann et al., Mantle Cell Lymphoma, pp.461-476, In Non-Hodgkin's Lymphomas, P. Mauch et al., eds., LippincottWilliams & Wilkins, Philadelphia, Pa. (2004)).

Diagnosis of mantle-cell lymphoma involves examination of the peripheralblood as well as bone marrow and lymph node biopsies. In addition,cytogenetic studies and immunophenotyping are useful in differentialdiagnosis. (See, W. Hiddemann, et al., Mantle Cell Lymphoma pp. 461-476,In Non-Hodgkin's Lymphomas, P. Mauch, et al., eds., Lippincott Williams& Wilkins, Philadelphia, Pa. (2004); D. Weisenburger, et al., MantleCell Lymphoma, pp. 28-41, In Malignant Lymphoma, B. Hancock, et al.,eds., Oxford University Press, New York, N.Y. (2000)).

5.21.2.3. Burkitt's Lymphoma

Burkitt's lymphoma is an aggressive B cell lymphoma typically observedin children and young adults and is usually associated with bulkydisease of the jaw and/or abdomen. Approximately 20% of patients havebone marrow involvement. An endemic form of Burkitt's lymphoma involvesEpstein-Barr virus (EBV) infection of malignant cells; the sporadic formis independent of EBV infection. A translocation of c-myc toimmunoglobulin loci, which results in deregulation of the c-myc gene, ischaracteristic of this disease (t(8;14)(q24;q32)). Interestingly,deletions of the c-myc sequences appear to be involved in the sporadicform of the disease, while the endemic form usually involves pointmutations or insertions. (See, V. Pappa, et al., Molecular Biology, pp.133-157, In Malignant Lymphoma, B. Hancock, et al., eds., OxfordUniversity Press, New York, N.Y. (2000)). Burkitt's lymphoma is alsocharacterized by SHM, and the malignant cells have a gene expressionprofile similar to GC B cells, suggesting that this malignancy isderived from GC B cells.

Immunophenotype of Burkett's lymphoma shows the cells of this diseaseexpress CD22, CD20, CD22, and CD79a, but not CD5, CD23, cyclin D orterminal deoxynucleotidyl transferase. Frequently, these cells arepositive for CD10 and BCL6 and usually negative for BCL2. (See, I.Magrath, et al., Burkitt's Lymphoma, pp. 477-501, In Non-Hodgkin'sLymphomas, P. Mauch, et al., eds., Lippincott Williams & Wilkins,Philadelphia, Pa. (2004)).

High grade B cell Burkitt's-like lymphoma is a lymphoma borderlinebetween Burkitt's lymphoma and large B cell lymphoma. The cells of thislymphoma express CD22 and CD20 but expression of CD10, which is nearlyalways present in true Burkitt's lymphoma, is frequently absent. Becauseof this and other characteristics, some believe this lymphoma should beclassified as a diffuse large B cell lymphoma. (See, K. Maclennan,Diffuse Aggressive B cell Lymphoma, pp. 49-54, In Malignant Lymphoma, B.Hancock, et al., eds., Oxford University Press, New York, N.Y. (2000)).

Diagnosis of Burkitt's lymphoma generally relies on detection of thetranslocation associated with this lymphoma; thus, conventionalcytogenetic analysis is usually performed. Long distance polymerasechain reaction techniques and fluorescent in situ hybridization (FISH)have been used to detect Ig-myc junctions in the translocations andother genetic alterations associated with this disease. (See, R.Siebert, et al., Blood 91:984-990 (1998); T. Denyssevych, et al.,Leukemia, 16:276-283 (2002)).

5.21.2.4. Diffuse Large B-Cell Lymphoma (DLBCL)

DLBCL is the most common non-Hodgkin's lymphoma and can arise from smallB cell lymphoma, follicular lymphoma or marginal zone lymphoma.Typically, patients present with lymphadenopathy; however, a largepercent of patients present in extranodal sites as well, withgastrointestinal involvement being the most common. Bone marrowinvolvement is observed in about 15% of patients. (See, Armitage, etal., Diffuse Large B cell Lymphoma, pp. 427-453, In Non-Hodgkin'sLymphomas, P. Mauch, et al., eds., Lippincott Williams & Wilkins,Philadelphia, Pa. (2004)). Heterogeneity in clinical, biological andmorphological characteristics makes this group of lymphomas difficult tosubclassify. However, two distinct subgroups have been identified withone expressing genes characteristic of germinal center B cells(GC-DLBCL) and the other overexpressing genes in peripheral blood Bcells. Survival rates are significantly better for patients withGC-DLBCL than those with activated B cell type (ABC)-DLBCL. (See, W.Chan, Archives of Pathology and Laboratory Medicine 128(12): 1379-1384(2004)).

DLBCLs express the cell surface antigens CD22, CD20, CD22, and CD79a.CD10 is expressed in the large majority of cases and CD5 expression isobserved in about 10% of cases. (See, K. Maclennan, Diffuse Aggressive Bcell Lymphoma, pp. 49-54, In Malignant Lymphoma, B. Hancock, et al.,eds., Oxford University Press, New York, N.Y. (2000)). DLBCL is oftenmarked by abnormalities of BCL6 and/or translocations of BCL2 to the IgHlocus. GC B cell like (GC) DLBCL is characterized by SHM with highlymutated immunoglobulin genes and ongoing SHM in malignant clones with aGC B cell-like gene expression profile. Most GC DLBCL have undergoneimmunoglobulin class switching. ABC-DLBCL is characterized by high levelexpression of NF-κB target genes including BCL2, interferon regulatoryfactor 4, CD44, FLIP and cyclin D. SHM, but not ongoing SHM, is present,and ABC-DLBCL does not have a GC B cell gene expression profile. Almostall ABC-DLBCL express a high level of IgM.

5.21.2.5. Extranodal Marginal-Zone Lymphoma

Extranodal marginal-zone lymphoma is an extranodal lymphoma that occursin organs normally lacking organized lymphoid tissue (e.g., stomach,salivary glands, lungs and thyroid glands). It is largely a disease thataffects older adults with a median age of over 60 years. Often, chronicinflammation or autoimmune processes precede development of thelymphoma. Gastric mucosal-associated lymphoid tissue (MALT) lymphoma,the most common type of marginal-zone lymphoma, is associated withHelicobacter pylori infection. Studies have shown a resolution ofsymptoms with eradication of the H. pylori infection following anantibiotic regimen. The presenting symptoms for gastric MALT lymphomainclude nonspecific dyspepsia, epigastric pain, nausea, gastrointestinalbleeding and anemia. Systemic symptoms are uncommon, as are elevatedlevels of lactate acid dehydrogenase. (See, J. Yahalom, et al.,Extranodal Marginal Zone B cell Lymphoma of Mucosa-Associated LymphoidTissue, pp. 345-360, In Non-Hodgkin's Lymphomas, P. Mauch, et al., eds.,Lippincott Williams & Wilkins, Philadelphia, Pa. (2004); J. Radford,Other Low-Grade Non-Hodgkin's Lymphomas, pp. 325-330, In MalignantLymphoma, B. Hancock, et al., eds., Oxford University Press, New York,N.Y. (2000). Systemic B symptoms include fevers greater than 38° C. forlonger than 2 weeks without sign of infection, night sweats, extremefatigue or unintentional weight loss of greater than or equal to 10% ofbody weight over the previous 6 months).

The immunophenotye of MALT lymphoma is characterized by expression ofCD20, CD79a, CD21 and CD35 and lack of expression of CD5, CD23, andCD10. About half of MALT lymphomas express CD43. The immunoglobulintypically expressed in the tumor cells of this disease is IgM while IgDis not expressed. These features are critical in distinguishing thislymphoma from other small B cell lymphomas such as mantle cell lymphoma,lymphocytic lymphoma and follicular lymphoma. Trisomy 3 has beenreported in 60% of MALT lymphoma cases. In 25-40% of gastric andpulmonary MALT lymphomas a t(11;18) is observed. This translocation isobserved much less frequently in other MALT lymphomas. T(11;18) isassociated with nuclear expression of BCL10. (See, J. Yahalom, et al.,Extranodal Marginal Zone B cell Lymphoma of Mucosa-Associated LymphoidTissue, pp. 345-360, In Non-Hodgkin's Lymphomas, P. Mauch, et al., eds.,Lippincott Williams & Wilkins, Philadelphia, Pa. (2004)). Marginal-zonelymphomas are generally characterized by SHM and ongoing SHM.

Diagnostic procedures include immunophenotyping or flow cytometry todetermine the identity of the cell surface markers. In addition,molecular genetic analysis should be done to determine the presence oft(11;18) as this is an indicator that the disease will not respond toantibiotics. Histology can be used to determine the presence of H.pylori. Additional tests should include a complete blood count, basicbiochemical tests including that for lactate acid dehydrogenase; CTscans of the abdomen, chest and pelvis and a bone marrow biopsy. (See,J. Yahalom, et al., Extranodal Marginal Zone B cell Lymphoma ofMucosa-Associated Lymphoid Tissue, pp. 345-360, In Non-Hodgkin'sLymphomas, P. Mauch, et al., eds., Lippincott Williams & Wilkins,Philadelphia, Pa. (2004)).

5.21.2.6. Nodal Marginal Zone B Cell Lymphoma

Nodal Marginal Zone B cell Lymphoma is a relatively newly classifiedlymphoma thus little has been published on it. It is a primary nodal Bcell lymphoma sharing genetic and morphological characteristics withextranodal and splenic marginal zone lymphomas, but does not localize tothe spleen or extranodally. Hepatitis C virus has been reported to beassociated with this lymphoma as has Sjögren's syndrome. (See, F.Berger, et al., Nodal Marginal Zone B cell Lymphoma, pp. 361-365, InNon-Hodgkin's Lymphomas, P. Mauch, et al., eds., Lippincott Williams &Wilkins, Philadelphia, Pa. (2004)).

Nodal marginal zone lymphoma has a heterogeneous cytology andmorphology. Due to its relatively high proportion of large cells thislymphoma, unlike the other marginal lymphomas (splenic and extranodal),cannot be classified as true low grade B cell lymphoma. The genetic andimmunological phenotype of nodal marginal zone lymphoma includesexpression of CD22, CD20, BCL2, sIgM and cytoplasmic IgG (cIg). Thesecells do not express CD5, CD10, CD23, CD43 or cyclin D1. Thetranslocation characteristic of MALT lymphoma, t(11;18), is not observedfor nodal marginal zone lymphoma. These characteristics aid in thedifferential diagnosis of this lymphoma from other small B celllymphomas. (See, F. Berger, et al., Nodal Marginal Zone B cell Lymphoma,pp. 361-365, In Non-Hodgkin's Lymphomas, P. Mauch, et al., eds.,Lippincott Williams & Wilkins, Philadelphia, Pa. (2004)).

5.21.2.7. Splenic Marginal Zone Lymphoma

Splenic Marginal Zone Lymphoma is an indolent micro-nodular B celllymphoma with a characteristic clinical presentation of prominentsplenomegaly and infiltration of the peripheral blood and the bonemarrow. In addition, a relatively high level of liver involvement hasbeen reported. A role for hepatitis C virus has been postulated for thislymphoma. The immunophenotype of splenic marginal zone lymphoma istypically CD20⁺, IgD⁺, BCL2⁺, p27⁺, CD3⁻, CD5⁻, CD10⁻, CD23⁻, CD38⁻,CD43⁻, BCL-6⁻, and cyclin D1⁻. Genetic characteristics include a 7qdeletion, p53 alterations and SHM. (See, M. Piris, et al., SplenicMarginal Zone Lymphoma, pp. 275-282, In Non-Hodgkin's Lymphomas, P.Mauch, et al., eds., Lippincott Williams & Wilkins, Philadelphia, Pa.(2004)).

Diagnosis generally relies on immunophenotyping to determine theidentity of the cell surface markers. Genetic and biochemical analysis,in combination with data on cell surface markers, help to differentiatethis lymphoma from other small B cell lymphomas. (See, M. Piris, et al.,Splenic Marginal Zone Lymphoma, pp. 275-282, In Non-Hodgkin's Lymphomas,P. Mauch, et al., eds., Lippincott Williams & Wilkins, Philadelphia, Pa.(2004)).

5.21.2.8. Acute (B Cell) Lymphocytic Leukemia (ALL)

ALL is a marrow-based neoplasm largely affecting children with thehighest incidence between 1-5 years. Most common symptoms atpresentation include fatigue, lethargy, fever and bone and joint pain.Fatigue and lethargy correlates with the degree of anemia present. Anelevated white blood cell count is common at presentment. Radiographs ofthe chest often show skeletal lesions. Extramedullary spread is commonand involves the central nervous system, testes, lymph nodes, liver,spleen and kidney. Anterior mediastinal masses are observed in onlyabout 5-10% of newly diagnosed cases. (See, J. Whitlock, et al., AcuteLymphocytic Leukemia, pp. 2241-2271, In Wintrobe's Clinical Hematology,Tenth Edition, G. Lee, et al., eds. Williams & Wilkins, Baltimore, Md.(1999)).

The immunophenotype of ALL is CD10⁺, CD22⁺, CD20⁺, and CD24⁺. Pre-B cellALL cells express cytoplasmic but not surface immunoglobulin, whilemature B cell ALL (which accounts for only 1-2% of ALL cases) isdistinguished from other leukemias of B cell lineage by the expressionof surface immunoglobulin. Cytogenetic characteristics of ALL includest(8;14), t(2;8) and t(8;22). Although rarely detected at the cytogeneticlevel t(12;21) may be the most common cytogenetic abnormality associatedwith childhood ALL (observed in about 25% of cases). (See, M. Kinney, etal., Classification and Differentiation of the Acute Leukemias, pp.2209-2240, In Wintrobe's Clinical Hematology, Tenth Edition, G. Lee, etal., eds. Williams & Wilkins, Baltimore, Md. (1999); J Whitlock, et al.,Acute Lymphocytic Leukemia, pp. 2241-2271; In Wintrobe's ClinicalHematology, Tenth Edition, G. Lee, et al., eds. Williams & Wilkins,Baltimore, Md., (1999)).

Precise diagnosis of acute leukemia usually relies on a bone aspirateand biopsy. Aspirate smears are used for morphological, immunologicaland cytological assessments. The demonstration of lymphoblasts in thebone marrow is diagnostic of ALL. The presence of greater than 5%leukemic lymphoblast cells in the bone marrow confirms ALL diagnosis butmost require greater than 25% for a definitive diagnosis. Lumbarpunctures are used to diagnose central nervous system involvement. Serumuric acids levels and serum lactate dehydrogenase levels have been foundto be elevated in ALL. (See, M. Kinney, et al., Classification andDifferentiation of the Acute Leukemias, pp. 2209-2240, In Wintrobe'sClinical Hematology, Tenth Edition, G. Lee, et al., eds. Williams &Wilkins, Baltimore, Md. (1999); J. Whitlock, et al., Acute LymphocyticLeukemia, pp. 2241-2271; In Wintrobe's Clinical Hematology, TenthEdition, G. Lee, et al., eds. Williams & Wilkins, Baltimore, Md.,(1999)).

5.21.2.9. Chronic Lymphocytic Leukemia (CLL)/Small B Cell LymphocyticLymphoma (SLL)

CLL/SLL is the most common type of leukemia. When the disease involvesthe peripheral blood and bone marrow it is referred to as CLL. However,when the lymph nodes and other tissues are infiltrated by cells that areimmunologically and morphologically identical to those in CLL, but whereleukemic characteristics of the disease are absent, then the disease isreferred to as SLL. This disease largely afflicts the elderly with agreater incidence of the disease occurring in men than women. Painlesslymphadenopathy is the most common finding at presentation.Hypogammaglobulinemia is common with most cases of CLL/SLL exhibitingreduced levels of all immunoglobulins rather than any particularsubclass of immunoglobulins. Asymptomatic patients are frequentlydiagnosed during routine blood counts (lymphocyte count of over5000×10⁹/L). As many as 20% of CLL/SLL cases report B symptoms. Anadditional diagnostic feature is infiltration of the bone marrow by morethan 30% by immature lymphocytes. Lymph node biopsies generally showinfiltration of involved nodes with well-differentiated lymphocytes.Autoimmune phenomena are often associated with CLL/SLL includingautoimmune hemolytic anemia and immune thrombocytopenia. (See, J.Gribben, et al., Small B cell Lymphocytic Lymphoma/Chronic LymphocyticLeukemia and Prolymphocytic Leukemia, pp. 243-261, In Non-Hodgkin'sLymphomas, P. Mauch, et al., eds., Lippincott Williams & Wilkins,Philadelphia, Pa. (2004); K. Maclennan, Diffuse Indolent B cellNeoplasms, pp. 43-47, In Malignant Lymphoma, B. Hancock, et al., eds.,Oxford University Press, New York, N.Y. (2000); Clinical Oncology, A.Neal, et al., Neal, Hoskin and Oxford University Press, co-publ., NewYork, N.Y. (2003)).

In contrast with many of the low-grade B cell malignancies, nonrandomreciprocal translocations are rarely found in CLL/SLL. However, othercytogenetic abnormalities have been reported including deletions at13q14, 11q22-23 and 17q13, with the latter two involving the p53 locus.Approximately 20% of cases exhibit trisomy 12. An elevated level of 13-2microglobulin, higher levels of CD38 expression and the production oftumor necrosis factor-alpha are all characteristic of CLL/SLL. Theimmunophenotype of CLL/SLL is very diagnostic and includes weakexpression of surface immunoglobulin usually IgM, or IgM and IgG, aswell as expression of the cell antigens CD22, CD20 and usually CD5 andCD23. (See, J. Gribben, et al., Small B cell LymphocyticLymphoma/Chronic Lymphocytic Leukemia and Prolymphocytic Leukemia, pp.243-261, In Non-Hodgkin's Lymphomas, P. Mauch, et al., eds., LippincottWilliams & Wilkins, Philadelphia, Pa. (2004); K. Maclennan, DiffuseIndolent B cell Neoplasms, pp. 43-47, In Malignant Lymphoma, B. Hancock,et al., eds., Oxford University Press, New York, N.Y. (2000)).

5.21.2.10. B Cell Prolymphocytic Leukemia (PLL)

PLL, once considered a variant of CLL, is now understood to be adistinct disease. PLL is generally a disease of elderly men and ischaracterized by a very high white blood cell count (greater than200×10⁹/L) and splenomegaly. Additional symptoms include anemia andthrombocytopenia. Prolymphocytes in PLL comprise more than 55% of thecells in the blood and bone marrow. In contrast with CLL, autoimmunephenomena are rarely observed in PLL. (See, J. Gribben, et al., Small Bcell Lymphocytic Lymphoma/Chronic Lymphocytic Leukemia andProlymphocytic Leukemia, pp. 243-261, In Non-Hodgkin's Lymphomas, P.Mauch, et al., eds., Lippincott Williams & Wilkins, Philadelphia, Pa.(2004)).

The immunophenotype of PLL is characterized by expression of CD22, CD21,CD22, CD24 and FMC7. The cells of PLL do not express CD23 and most donot express CD5. PLL cells exhibit complex chromosomal abnormalities,with deletions at 13q14 and 11q23 being some of the most frequent. Thepattern of p53 mutation in PLL cells is different from that observed forCLL. Differential diagnosis usually relies on complete blood count,histological, immunophenotypic, and genetic analyses. (See, J. Gribben,et al., Small B cell Lymphocytic Lymphoma/Chronic Lymphocytic Leukemiaand Prolymphocytic Leukemia, pp. 243-261, In Non-Hodgkin's Lymphomas, P.Mauch, et al., eds., Lippincott Williams & Wilkins, Philadelphia, Pa.(2004)).

5.21.2.11. Hairy Cell Leukemia (HCL)

HCL is a rare, indolent chronic leukemia affecting more men than womenand largely those of middle age. The typical symptoms include massivesplenomegaly and pancytopenia. The peripheral blood and bone marrowcontain the typical “hairy cells,” which are B lymphocytes withcytoplasmic projections. Over 90% of HCL patients have bone marrowinfiltration. (See, Clinical Oncology, A. Neal, et al., Neal, Hoskin andOxford University Press, co-publ., New York, N.Y. (2003); J. Johnston,Hairy Cell Leukemia, pp. 2428-2446, In Wintrobe's Clinical Hematology,Tenth Edition, G. Lee et al., eds. Williams & Wilkins, Baltimore, Md.(1999)).

Cytogenetic analysis has shown that clonal abnormalities are present in19% of cases and involve numerical and structural abnormalities ofchromosomes 5, 7 and 14. The serum level of TNF-α is elevated in hairycell leukemia and correlates with tumor burden. Hairy cell leukemiacells express surface immunoglobulins (IgG and IgM) and CD11c, CD22,CD20, CD22 and typically CD25. In addition, FMC7, HC-2 and CD103 areexpressed. HCL cells do not express CD5 or CD10. Diagnosis generallyinvolves the use of bone marrow aspirates, cytogenetics, blood smearsand immunophenotyping. (See, Clinical Oncology, A. Neal, et al., Neal,Hoskin and Oxford University Press, co-publ., New York, N.Y. (2003); J.Johnston, Hairy Cell Leukemia, pp. 2428-2446, In Wintrobe's ClinicalHematology, Tenth Edition, G. Lee et al., eds. Williams & Wilkins,Baltimore, Md. (1999)).

5.21.2.12. Precursor B Cell Lymphoblastic Lymphoma/Pre-B Cell AcuteLymphoblastic Leukemia/Lymphoblastic Lymphoma

Precursor B cell lymphoblastic lymphoma/pre-B cell acute lymphoblasticleukemia/Lymphoblastic lymphoma is a disease of precursor T or B cells.The T and B cell lymphoblastic lymphomas are morphologically identical,but clinical distinctions may be made based on degree of bone marrowinfiltration or bone marrow involvement. 85-90% of lymphoblasticlymphomas are T-cell derived with the remainder being B cell derived.Lymphoblastic lymphoma has a median age of 20 years with a malepredominance. Peripheral lymph node involvement is a common feature atpresentation, occurring especially in the cervical, supraclavicular andaxillary regions. This disease frequently presents with bone marrowinvolvement. Central nervous system is less common at presentment butoften appears in cases of relapse. Other sites of involvement caninclude liver, spleen, bone, skin, pharynx and testes (See, J.Sweetenham, et al., Precursor B- and T-Cell Lymphoblastic Lymphoma, pp.503-513, In Non-Hodgkin's Lymphomas, P. Mauch, et al., eds., LippincottWilliams & Wilkins, Philadelphia, Pa. (2004)).

Precursor B cell lymphoblastic lymphomas express immature markers B cellmarkers such as CD99, CD34 and terminal deoxynucleotidyl transferase.These cells also express CD79a, CD22, and sometimes CD20 and typicallylack expression of CD45 and surface immunoglobulin. Translocations at11q23, as well as t(9;22)(q34;q11.2) and t(12;21)(p13;q22), have beenassociated with poor prognosis. Good prognosis is associated withhyperdiploid karyotype, especially that associated with trisomy 4, 10,and 17 and t(12;21)(p13;q22). (See, J. Sweetenham, et al., Precursor B-and T-Cell Lymphoblastic Lymphoma, pp. 503-513, In Non-Hodgkin'sLymphomas, P. Mauch, et al., eds., Lippincott Williams & Wilkins,Philadelphia, Pa. (2004)).

Diagnostic tests include lymph node biopsies, blood tests, x-rays, CTscans, and lumbar punctures to examine the cerebralspinal fluid formalignant cells.

5.21.2.13. Primary Mediastinal Large B Cell Lymphoma

Primary mediastinal large B cell lymphoma is a diffuse large B celllymphoma occurring predominantly in young women and characterized by alocally invasive anterior mediastinal mass originating in the thymus.Distant spread to peripheral nodes and bone marrow involvement isunusual. Systemic symptoms are common. While this disease resemblesnodal large cell lymphomas, it has distinct genetic, immunological, andmorphological characteristics.

The immunophenotype of tumor cells of primary mediastinal large B celllymphoma are often surface immunoglobulin negative but do express such Bcell associated antigens as CD22, CD20, CD19, and CD79a. CD10 and BCL6are also commonly expressed. Expression of plasma cell associatedmarkers CD15, CD30, epithelial membrane antigen (EMA) is rare. BCL6 andc-myc gene arrangements are also uncommon. The presence of clonalimmunoglobulin rearrangements, immunoglobulin variable region and genehypermutation along with BCL6 hypermutation suggest that this lymphomaderives from a mature germinal center or post-germinal center B cell.The chromosomal translocations that seem to be associated with tumors ofthis disease are similar to those observed in other forms of diffuselarge cell lymphoma. (See, P. Zinzani, et al., Primary Mediastinal LargeB cell Lymphoma, pp. 455-460, In Non-Hodgkin's Lymphomas, P. Mauch, etal., eds., Lippincott Williams & Wilkins, Philadelphia, Pa. (2004)).

The diagnostic evaluation for primary mediastinal large B cell lymphomagenerally includes a complete physical examination, completehematological and biochemical analysis, total-body computerizedtomography and bone marrow biopsy. Gallium-67 scanning is a useful testfor staging, response to treatment and for assessment of relapse. (See,P. Zinzani et al., Primary Mediastinal Large B cell Lymphoma, pp.455-460, In Non-Hodgkin's Lymphomas, P. Mauch, et al., eds., LippincottWilliams & Wilkins, Philadelphia, Pa. (2004)).

5.21.2.14. Lymphoplasmacytic Lymphoma (LPL)/LymphoplasmacyticImmunocytoma/Waldström's Macroglobulinemia

LPL/Lymphoplasmacytic immunocytoma/Waldström's Macroglobulinemia is anodal lymphoma that is usually indolent, and often involves bone marrow,lymph nodes and spleen. This is generally a disease of older adults withmales slightly predominating. Most patients have monoclonal IgMparaprotein in their serum (>3 g/dL) resulting in hyperviscosity of theserum. Tumor cells have a plasmacytic morphology. A subset of LPL ischaracterized by recurrent translocations between chromosomes 9 and 14,which involves the PAX5 and immunoglobulin heavy-chain loci. LPL ischaracterized by SHM as well as ongoing SHM, and is believed to bederived from post-GC B cells. (See, A. Rohatiner, et al.,Lymphoplasmacytic Lymphoma and Waldström's Macroglobulinemia, pp.263-273, In Non-Hodgkin's Lymphomas, P. Mauch, et al., eds., LippincottWilliams & Wilkins, Philadelphia, Pa. (2004); K. Maclennan, DiffuseIndolent B cell Neoplasms, pp. 43-47, In Malignant Lymphoma, B. Hancock,et al., eds., Oxford University Press, New York, N.Y. (2000); A. Lal, etal., Role of Fine Needle Aspiration in Lymphoma, pp. 181-220, In W.Finn, et al., eds., Hematopathology in Oncology, Kluwer AcademicPublishers, Norwell, Mass. (2004)).

The immunophenotype of this disease shows expression of the B cellassociated antigens CD22, CD20, CD19, and CD79a and a lack of expressionof CD5, CD10, and CD23. Presence of strong surface immunoglobulin andCD20, the lack of expression of CD5, and CD23 and the presence ofcytoplasmic immunoglobulin are characteristics that aid indistinguishing this disease from chronic lymphocytic leukemia. Alsodiagnostic of this disease is t(9;14)(p13;q32). (See, A. Rohatiner, etal., Lymphoplasmacytic Lymphoma and Waldström's Macroglobulinemia, pp.263-273, In Non-Hodgkin's Lymphomas, P. Mauch, et al., eds., LippincottWilliams & Wilkins, Philadelphia, Pa. (2004); K. Maclennan, DiffuseIndolent B cell Neoplasms, pp. 43-47, In Malignant Lymphoma, B. Hancock,et al., eds., Oxford University Press, New York, N.Y. (2000); R.Chaganti, et al., Cytogenetics of Lymphoma, pp. 809-824, InNon-Hodgkin's Lymphomas, P. Mauch, et al., eds., Lippincott Williams &Wilkins, Philadelphia, Pa. (2004)).

Diagnostic tests typically include a complete blood count, renal andliver function tests, CT scans, biopsy and aspiration of the bonemarrow, protein electrophoresis to quantify and characterize theparaprotein and serum viscosity. Measurement of β₂-microglobulin is usedas a prognostic test. (See, A. Rohatiner, et al., LymphoplasmacyticLymphoma and Waldström's Macroglobulinemia, pp. 263-273, InNon-Hodgkin's Lymphomas, P. Mauch, et al., eds., Lippincott Williams &Wilkins, Philadelphia, Pa. (2004)).

5.21.2.15. Null-Acute Lymphoblastic Leukemia

Null-acute lymphoblastic leukemia is a subset of ALL which lacks B- orT-cell characteristics. Phenotypic analysis of leukemic blasts shows atypical null ALL pattern, i.e., CD10 (common ALL antigen)-negative,strongly HLA-DR-positive, and CD22 (B4)-positive (see Katz et al. (1988)Blood 71(5):1438-47).

5.21.2.16. Hodgkin's Lymphoma

Hodgkin's lymphoma usually arises in the lymph nodes of young adults. Itcan be divided into classical subtype and a less common nodularlymphocytic predominant subtype. The classical type exhibits SHM, butnot ongoing SHM, and does not have a GC B cell gene expression profile.The nodular lymphocyte predominant type, in contrast, is characterizedby SHM and ongoing SHM and a GC B cell gene expression profile. Whilethe two types differ clinically and biologically, they do share certainfeatures such as a lack of neoplastic cells within a background ofbenign inflammatory cells. B. Schnitzer et al., Hodgkin Lymphoma, pp.259-290, In W. Finn and L. Peterson, eds., Hematopathology in Oncology,Kluwer Academic Publishers, Norwell, Mass. (2004)).

The most common features at presentation are painless enlargement oflymph nodes, usually in the neck, but occasionally in the inguinalregion. Waxing and waning of nodes is also characteristic of thisdisease. B symptoms are observed in about one-third of patients.Isolated extranodal involvement is rare and in cases where disseminationhas occurred extranodal involvement is observed about 10-20% of thetime. (See, P. Johnson et al., Hodgkin's Disease: Clinical Features, pp.181-204, In Malignant Lymphoma, B. Hancock, et al., eds., OxfordUniversity Press, New York, N.Y. (2000)).

Reed-Sternberg (RS) cells are the malignant cells of Hodgkin's lymphoma.RS cells and their variants express CD15, CD25, CD30 and transferrinreceptor. In addition these cells express polyclonal cytoplasmicimmunoglobulin. In most cases of Hodgkin's lymphoma the RS cells do notexpress CD45, a feature that aids in distinguishing this disease fromnon-Hodgkin's Lymphomas. Epstein Barr virus has been demonstrated to bepresent in Reed-Sternberg cells in about one-half of Hodgkin's lymphomacases but its role is unclear.

Diagnosis is most frequently made by lymph node biopsy. Additionaldiagnostic tests include a full blood count (often hematological testsare normal; white blood cell counts of less than 1.0×10⁹/L are seen inabout 20% of cases), erythrocyte sedimentation rate (often elevated inadvanced stages of the disease), biochemical tests includingelectrolytes, urea, creatinine, urate, calcium (hypercalcemia is rarebut when present is associated with extensive bone involvement), liverblood tests, lactate dehydrogenase (elevated levels often associatedwith advanced disease), albumin and beta₂-microglobulin (β2-M).Lymphanigiograms and chest x-rays and CT scans of the chest, abdomen andpelvis are important in identifying abnormal lymph nodes and the extentof extranodal involvement. Bone marrow biopsies are typically consideredoptional as bone marrow involvement is unusual and the results of suchbiopsies appear not to affect clinical management or prognosis.Splenechtomies are not usually performed today as it rarely influencesmanagement and CT or MRI imaging provides information on splenic status.Significantly elevated levels of p55, TNF and sICAM-1 are correlated tothe stage of the disease, presence of symptoms and complete responserate. (See, P. Johnson, et al., Hodgkin's Disease: Clinical Features,pp. 181-204, In Malignant Lymphoma, B. Hancock, et al., eds., OxfordUniversity Press, New York, N.Y. (2000); Clinical Oncology, A. Neal, etal., Neal, Hoskin and Oxford University Press, co-publ., New York, N.Y.(2003); R. Stein, Hodgkin's Disease, pp. 2538-2571, In Wintrobe'sClinical Hematology, Tenth Edition, G. Lee et al., eds. Williams &Wilkins, Baltimore, Md. (1999)).

5.21.2.17. Multiple Myeloma

Multiple myeloma is a malignancy of plasma cells. Neoplastic cells arelocated in the bone marrow, and osteolytic bone lesions arecharacteristic. Reciprocal chromosomal translocations between one of theimmunoglobulin loci and a variety of other genes, e.g., cyclin D1,cyclin D3, c-MAF, MMSET (multiple myeloma SET-domain protein) orfibroblast growth factor receptor 3 are believed to be the primaryoncogenic events. Multiple myeloma is characterized by SHM, and theputative cell of origin is a post-GC B cell. Multiple myeloma istypically first identified by symptoms such as recurrent infection,fatigue, pain, and kidney problems and is confirmed with clinicaltesting (see, for example, Cancer: Principles and Practice of Oncology.6th edition. DeVita, V. T., Hellman, S. and Rosenberg, S. A. editors.2001 Lippincott Williams and Wilkins Philadelphia, Pa. 19106 pp.2465-2499).

In certain embodiments, patients who are candidates for treatment by thecompositions and methods of the invention can undergo further diagnostictests on blood and/or urine to confirm the diagnosis or suspicion ofmultiple myeloma including, but not limited to, complete blood count(CBC) tests to determine if the types of cells reported in a CBC arewithin their normal ranges which are well known in the art, bloodchemistry profile to determine whether levels of various bloodcomponents, such as albumin, blood urea nitrogen (BUN), calcium,creatinine, and lactate dehydrogenase (LDH), deviate from standardvalues. Serum levels of beta₂-microglobulin (β₂-M) can also be examinedand surrogate markers for IL-6, a growth factor for myeloma cells.Urinalysis can be used to measure the levels of protein in the urine.Electrophoresis can be used to measure the levels of various proteins,including M protein in the blood (called serum protein electrophoresis,or SPEP) or urine (called urine electrophoresis, or UEP). An additionaltest, called immunofixation electrophoresis (IFE) orimmunoelectrophoresis, may also be performed to provide more specificinformation about the type of abnormal antibody proteins present.Assessing changes and proportions of various proteins, particularly Mprotein, can be used to track the progression of myeloma disease andresponse to treatment regimens. Multiple myeloma is characterized by alarge increase in M protein which is secreted by the myeloma tumorcells.

Diagnostic tests on bone can also be conducted to confirm the diagnosisor suspicion of multiple myeloma including, but not limited to, X-raysand other imaging tests—including a bone (skeletal) survey, magneticresonance imaging (MRI), and computerized axial tomography (CAT), alsoknown as computed tomography (CT)—can assess changes in the bonestructure and determine the number and size of tumors in the bone. Bonemarrow aspiration or bone marrow biopsy can be used to detect anincrease in the number of plasma cells in the bone marrow. Aspirationrequires a sample of liquid bone marrow, and biopsy requires a sample ofsolid bone tissue. In both tests, samples are preferably taken from thepelvis (hip bone). The sternum (breast bone) can also be used foraspiration of bone marrow.

Patients with multiple myeloma are typically categorized into thefollowing three groups that help define effective treatment regimens.Monoclonal gammopathy of undetermined significance (MGUS) is typicallycharacterized by a serum M protein level of less than 3 g/dL, bonemarrow clonal plasma cells of less than 10%, no evidence of other B celldisorders, and no related organ or tissue impairment, such ashypercalcemia (increased serum calcium levels), impaired kidney functionnoted by increased serum creatinine, anemia, or bone lesions.Asymptomatic myelomas are typically stage I and includes smolderingmultiple myeloma (SMM) and indolent multiple myeloma (IMM). SMM ischaracterized by serum M protein greater than or equal to 3 g/dL and IMMis characterized by bone marrow clonal plasma cells greater than orequal to 10% of the bone marrow cells. Symptomatic myeloma ischaracterized by M protein in serum and/or urine and includes Stage IImultiple myeloma characterized by the presence of bone marrow clonalplasma cells or plasmacytoma and Stage III multiple myelomacharacterized by related organ or tissue impairment.

Osteosclerotic myeloma is a component of the rare POEMS syndrome(polyneuropathy, organomegaly, endocrinopathy, monoclonal gammopathy andskin lesions). Peak incidence is at 40 to 50 years of age. Systemicfeatures include skeletal lesions, marrow-plasma cells<5%, a normal CBC,increased platelets, and organomegaly. The CSF has a high protein withno cells present. The M-protein levels are low (<3 g/dl, median=1.1g/dl); heavy chain class—usually α or γ; light chain class—usually λ;rare urine monoclonal and occasional cryoglobulinemia. Neuropathy occursin 50% of the patients with weakness both proximal and distal, sensoryloss is greater in larger than small fibers; and demyelination and longdistal latency.

Smoldering multiple myeloma patients generally present with stabledisease for months/years; no anemia, bone lesions, renal insufficiencyor hypercalcemia; have >10% plasma cells in bone marrow and monoclonalserum protein. The criteria for smoldering multiple myeloma iscompatible with the diagnosis of multiple myeloma; however, there is noevidence of progressive course. These are cases with a slow progression,the tumor cell mass is low at diagnosis and the percentage of bonemarrow plasma cells in S phase is low (<0.5%). Characteristic clinicalfeatures include: serum M protein levels>3 g/dL and/or bone marrowplasma cells≧10%; absence of anemia, renal failure, hypercalcemia, lyticbone lesions.

Indolent (or asymptomatic) multiple myeloma is a multiple myelomadiagnosed by chance in the absence of symptoms, usually after screeninglaboratory studies. Indolent multiple myeloma is similar to smolderingmyeloma but with few bone lesions and mild anemia. Most cases ofindolent multiple myeloma develop overt multiple myeloma within 3 years.Diagnostic criteria are the same as for multiple myeloma except: no bonelesions or one asymptomatic lytic lesion (X-ray survey); M componentlevel<3 g/dL for IgG, 2 g/dL for IgA urine light chain<4 g/24 h;hemoglobin>10 g/dl, serum calcium normal, serum creatinine<2 mg/dL, andno infections.

5.21.2.18. Solitary Plasmacytoma

Solitary plasmacytoma is one of a spectrum of plasma cell neoplasmswhich range from benign monoclonal gammopathy to solitary plasmacytomato multiple myeloma. Approximately seventy percent of all solitaryplasmacytoma cases eventually result in multiple myeloma. These diseasesare characterized by a proliferation of B cells which produce thecharacteristic paraprotein. Solitary plasmacytoma results in aproliferation of clonal plasma cells in a solitary site, usually asingle bone or extramedullary tissue site. Diagnostic criteria ofsolitary plasmacytoma include a histologically confirmed single lesion,normal bone biopsy, negative skeletal survey, no anemia, normal calciumand renal function. Most cases exhibit minimally elevated serumM-protein (paraprotein). The median age at diagnosis is 50-55, about5-10 years younger than the median age for multiple myeloma. (See, C.Wilson, The Plasma Cell Dycrasias, pp. 113-144, In W. Finn and L.Peterson, eds., Hematopathology in Oncology, Kluwer Academic Publishers,Norwell, Mass. (2004), S. Chaganti, et al., Cytogenetics of Lymphoma,pp. 809-824, In Non-Hodgkin's Lymphomas, P. Mauch, et al., eds.,Lippincott Williams & Wilkins, Philadelphia, Pa., (2004)).

The immunophenotypic and genetic features of plasmacytoma appear to besimilar to multiple myeloma.

5.21.2.19. Light Chain Disease/Light Chain Deposition Disease (LCDD)

LCDD is a plasma cell dycrasias disorder caused by the over-synthesis ofimmunoglobulin light chains (usually kappa light chains) that aredeposited in tissues. Patients commonly present with organ dysfunction,weakness, fatigue and weight loss. In approximately 80% of cases of LCDDa monoclonal immunoglobulin is detected. Detection of monoclonal kappalight chains using immunofluorescent techniques is limited by thetendency of light chains to give excess background staining, therefore,ultrastructural immunogold labeling may be necessary. (See, C. Wilson,The Plasma Cell Dycrasias, pp. 113-144, In W. Finn and L. Peterson,eds., Hematopathology in Oncology, Kluwer Academic Publishers, Norwell,Mass. (2004)).

5.21.2.20. Plasma cell leukemia (PCL),

PCL, a plasma cell dycrasias, is a rare aggressive variant of multiplemyeloma. The criteria for plasma cell leukemia is a peripheral bloodabsolute plasma cell count of greater than 2×10⁹/L or plasma cellsgreater than 20% of white blood cells. Determination of the presence ofa CD138⁺ population with cytoplasmic light chain restriction by flowcytometry will distinguish PCL from lymphoid neoplasm with plasmacyticfeatures. PCL cells are also characterized by the lack of surface lightchain and CD22 expression, and either no or weak expression of CD45.About 50% of cases of PCL express CD20 and about 50% lack expression ofCD56. The genetic abnormalities observed in PCL patients are the same asthose observed for multiple myeloma patients but they are found athigher frequency in PCL. (See, C. Wilson, The Plasma Cell Dycrasias, pp.113-144, In W. Finn and L. Peterson, eds., Hematopathology in Oncology,Kluwer Academic Publishers, Norwell, Mass., (2004)).

Plasma cell leukemia has two forms: if initial diagnosis is based onleukemic phase of myeloma then the primary form is present, otherwise itis secondary. Primary plasma cell leukemia is associated with a youngerage, hepatosplenomegaly, lymphadenopathy, and fewer lytic bone lesionsbut poorer prognosis than the secondary form. The peripheral blood ofplasma cell leukemic patients has greater than 20% plasma cells withabsolute count of 2000/ml or more.

5.21.2.21. Monoclonal Gammopathy of Unknown Significance (MGUS)

MGUS is a relatively common condition characterized by the presence ofelectrophoretically homogeneous immunoglobulins or benign M-components.The occurrence of this condition appears to increase with age. Mostindividuals carrying the M-components never develop malignant plasmacell dycrasias, such as multiple myeloma. However, some individuals withthis condition have associated malignant conditions. When symptomatic,patients can have enlarged liver or spleen and pleuroneuropathy. (See,J. Foerster, Plasma Cell Dycrasias General Considerations, pp.2612-2630, In Wintrobe's Clinical Hematology, Tenth Edition, G. Lee etal., eds. Williams & Wilkins, Baltimore, Md. (1999)).

MGUS can be differentiated from multiple myeloma by the presence ofincreased number of monoclonal plasma cells circulating in theperipheral blood. The serological characteristics of M-components areidentical to other plasma cell dycrasias conditions, however, the totalconcentration of M-component is usually less than 30 g/L. Theparaprotein is usually IgG; however multiple paraproteins may be presentincluding IgG, IgA, IgM. The relative amount of each of the individualimmunoglobulin classes is typically proportional to that found in normalserum. Proteinemia or proteinuria is rare. Serial measurements ofM-protein levels in the blood and urine, and continued monitoring of theclinical and laboratory features (including protein electrophoresis) isthe most reliable method of differentiating MGUS from early stage plasmacell dycrasias. In Wintrobe's Clinical Hematology, Tenth Edition, G. Leeet al., eds. Williams & Wilkins, Baltimore, Md. (1999)).

5.21.2.22. Mature B Cell Malignancies:

In one aspect of the invention, the inventive anti-CD22 antibodycompositions can deplete mature B cells. Thus, as another aspect, theinvention can be practiced to treat mature B cell malignancies includingbut not limited to follicular lymphoma, mantle-cell lymphoma, Burkitt'slymphoma, multiple myeloma, diffuse large B-cell lymphoma (DLBCL)including germinal center B cell-like (GCB) DLBCL, activated B cell-like(ABC) DLBCL, and type 3 DLBCL, Hodgkin's lymphoma including classicaland nodular lymphocyte pre-dominant type, lymphoplasmacytic lymphoma(LPL), marginal-zone lymphoma including gastric mucosal-associatedlymphoid tissue (MALT) lymphoma, and chronic lymphocytic leukemia (CLL)including immunoglobulin-mutated CLL and immunoglobulin-unmutated CLL.

5.21.2.23. Pre-B Cell Malignancies:

Further, CD22 is expressed earlier in B cell development than, forexample, CD20, and is therefore particularly suited for treating pre-Bcell and immature B cell malignancies, e.g., in the bone marrow.Representative pre-B cell and immature B cell malignancies include butare not limited to mantle cell lymphoma, pre-B cell acute lymphoblasticleukemia, precursor B cell lymphoblastic lymphoma, and othermalignancies characterized by CD22 expression.

5.22. Patient Diagnosis and Therapeutic Regimens Transplantation

According to certain aspects of the invention, the treatment regimen anddose used with the compositions and methods of the invention is chosenbased on a number of factors including, for example, clinicalmanifestation that place a patient at risk for developing a humoralrejection, or clinical evidence that such a rejection is developing. Theterms “humoral” and “antibody-mediated” are used interchangeably herein.

The criteria for assessing the risk that a patient will develop ahumoral rejection are established according to the knowledge and skillin the art. In one embodiment, a positive complement dependentcytotoxicity or antiglobulin enhanced complement dependent cytotoxicitycrossmatch indicates that a patient is at high risk for humoralrejection. In one embodiment, a positive crossmatch or a prior positivecomplement dependent cytotoxicity or anti-globulin enhanced complementdependent cytotoxicity crossmatch indicates that a patient is at anintermediate risk for humoral rejection. In one embodiment, a negativecrossmatch indicates that a patient is at a low risk for humoralrejection.

In another embodiment, a transplant recipient in need of prophylaxisagainst graft rejection may be identified as a patient or patientpopulation having detectable circulating anti-HLA alloantibodies priorto transplantation. In another example, the patient or patientpopulation is identified as having panel reactive antibodies prior totransplantation. The presence of detectable circulating anti-HLAalloantibodies in a transplant recipient post-transplantation can alsobe used to identify the patient or patient population in need oftreatment for humoral rejection according to the invention. The patientor patient population in need of treatment for humoral rejection canalso be identified according to other clinical criteria that indicatethat a transplant recipient is at risk for developing a humoralrejection or has already developed a humoral rejection. For example, atransplant recipient in need of treatment of humoral rejection may beidentified as a patient or population in an early stage of humoralrejection, such as a latent humoral response characterized bycirculating anti-donor alloantibodies. An early stage of humoralrejection may also be a silent reaction characterized by circulatinganti-donor alloantibodies and C4d deposition, or a subclinical rejectioncharacterized by circulating anti-donor alloantibodies, C4d deposition,and tissue pathology. In later stages, the recipient is identified as apatient or patient population presenting with clinical indications ofhumoral rejection characterized according to the knowledge and skill inthe art, for example, by circulating anti-donor alloantibodies, C4ddeposition, tissue pathology, and graft dysfunction.

The present invention provides compositions, therapeutic formulations,methods and regimens effective to reduce the incidence, severity, orduration of GVHD, a rejection episode, or post-transplantlymphoproliferative disorder. In certain embodiments, the compositionsand methods of the invention are effective to attenuate the hostresponse to ischemic reperfusion injury of a solid tissue or organgraft. In a preferred embodiment, that anti-CD22 antibody compositionsand methods of the invention are effective to prolong survival of agraft in a transplant recipient.

The present invention encompasses grafts that are autologous,allogeneic, or xenogeneic to the recipient. The types of graftsencompassed by the invention include tissue and organ grafts, includingbut not limited to, bone marrow grafts, peripheral stem cell grafts,skin grafts, arterial and venous grafts, pancreatic islet cell grafts,and transplants of the kidney, liver, pancreas, thyroid, and heart. Theterms “graft” and “transplant” are used interchangeably herein. In oneembodiment, the autologous graft is a bone marrow graft, an arterialgraft, a venous graft or a skin graft. In one embodiment, the allograftis a bone marrow graft, a corneal graft, a kidney transplant, apancreatic islet cell transplant, or a combined transplant of a kidneyand pancreas. In one embodiment, the graft is a xenograft, preferablywherein the donor, is a pig. The compositions and methods of the presentinvention may also be used to suppress a deleterious immune response toa non-biological graft or implant, including but not limited to anartificial joint, a stent, or a pacemaker device.

The anti-CD22 antibodies, compositions, and methods of the invention canbe used to treat or prevent GVHD, humoral rejection, or post-transplantlymphoproliferative disorder without regard to the particularindications initially giving rise to the need for the transplant or theparticular type of tissue transplanted. However, the indications whichgave rise to the need for a transplant and the type of tissuetransplanted by provided basis for a comprehensive therapeutic regimenfor the treatment or prevention of GVHD, graft rejection, andpost-transplant lymphoproliferative disorder, which comprehensiveregimen comprises the anti-CD22 antibody compositions and methods of theinvention.

Therapeutic formulations and regimens of the present invention aredescribed for treating human subjects diagnosed with autoimmune diseasesor disorders, including but not limited to, rheumatoid arthritis, SLE,ITP, pemphigus-related disorders, diabetes, and scleroderma.

Appropriate treatment regimens can be determined by one of skill in theart for the particular patient or patient population. In particularembodiments, the treatment regimen is a pre-transplant conditioningregimen, a post-transplant maintenance regimen, or post-transplanttreatment regimen for an acute or a chronic rejection. In certainembodiments, the particular regimen is varied for a patient who isassessed as being at a high or intermediate risk of developing a humoralresponse, compared with the regimen for a patient who is assessed asbeing at a low risk of developing a humoral response.

In certain embodiments, the particular regimen is varied according tothe stage of humoral rejection, with more aggressive therapy beingindicated for patients at later stages of rejection. The stages ofhumoral rejection may be classified according to the knowledge and skillin the art. For example, the stages of humoral rejection may beclassified as one of stages I to IV according to the following criteria:Stage I Latent Response, characterized by circulating anti-donoralloantibodies, especially anti-HLA antibodies; Stage II SilentReaction, characterized by circulating anti-donor alloantibodies,especially anti-HLA antibodies, and C4d deposition, but withouthistologic changes or graft dysfunction; Stage III SubclinicalRejection: characterized by circulating anti-donor alloantibodies,especially anti-HLA antibodies, C4d deposition, and tissue pathology,but without graft dysfunction; Stage IV Humoral Rejection: characterizedby circulating anti-donor alloantibodies, especially anti-HLAantibodies, C4d deposition, tissue pathology, and graft dysfunction.

Dose response curves can be generated using standard protocols in theart in order to determine the effective amount of the compositions ofthe invention for use in a particular regimen, for example, inconditioning regimens prior to transplantation, and inpost-transplantation regimens for prophylaxis and treatment of GVHD,humoral rejection, or post-transplantation lymphoproliferativedisorders. In general, patients at high risk for developing a humoralrejection and those already exhibiting one or more clinical indicatorsof rejection will require higher doses and/or more frequent doses whichmay be administered over longer periods of time in comparison topatients who are not at high risk or who do not exhibit any indicationsof active rejection.

The anti-CD22 antibodies, compositions and methods of the invention canbe practiced to treat or prevent GVHD, humoral rejection, orpost-transplantation lymphoproliferative disorders, either alone or incombination with other therapeutic agents or treatment regimens. Othertherapeutic regimens for the treatment or prevention of GVHD, humoralrejection, or post-transplantation lymphoproliferative disorders maycomprise, for example, one or more of anti-lymphocyte therapy, steroidtherapy, antibody depletion therapy, immunosuppression therapy, andplasmapheresis.

Anti-lymphocyte therapy may comprise the administration to thetransplant recipient of anti-thymocyte globulins, also referred to asthymoglobulin. Anti-lymphocyte therapy may also comprise theadministration of one or more monoclonal antibodies directed against Tcell surface antigens. Examples of such antibodies include, withoutlimitation, OKT3™ (muromonab-CD3), CAMPATH™-1H (alemtuzumab),CAMPATHT™-1G, CAMPATH™-1M, SIMULECT™ (basiliximab), and ZENAPAX™(daclizumab). In a specific embodiment, the anti-lymphocyte therapycomprises one or more additional antibodies directed against B cells,including, without limitation, RITUXAN™ (rituximab).

Steroid therapy may comprise administration to the transplant recipientof one or more steroids selected from the group consisting of cortisol,prednisone, methyl prednisolone, dexamethazone, and indomethacin.Preferably, one or more of the steroids are corticosteroids, includingwithout limitation, cortisol, prednisone, and methylprednisolone.

Antibody depletion therapy may include, for example, administration tothe transplant recipient of intravenous immunoglobulin. Antibodydepletion therapy may also comprise immunoadsorption therapy applied tothe graft ex vivo, prior to transplantation. Immunoadsorption may beaccomplished using any suitable technique, for example, protein Aaffinity, or antibody based affinity techniques using antibodiesdirected against T cell or B cell surface markers such as anti-CD3antibodies, anti-CD22 antibodies, anti-CD20 antibodies, and anti-CD22antibodies.

Immunosuppression therapy may comprise the administration of one or moreimmunosuppressive agents such as inhibitors of cytokine transcription(e.g., cyclosporin A, tacrolimus), nucleotide synthesis (e.g.,azathiopurine, mycophenolate mofetil), growth factor signal transduction(e.g., sirolimus, rapamycin), and the T cell interleukin 2 receptor(e.g., daclizumab, basiliximab). In a particular embodiment, animmunosuppressant agent used in combination with the compositions andmethods of the invention includes one or more of the following:adriamycin, azathiopurine, busulfan, cyclophosphamide, cyclosporin A(“CyA”), cytoxin, fludarabine, 5-fluorouracil, methotrexate,mycophenolate mofetil (MOFETIL), nonsteroidal anti-inflammatories(NSAIDs), rapamycin, and tacrolimus (FK506). Immunosuppressive agentsmay also comprise inhibitors of complement, for example, solublecomplement receptor-1, anti-C5 antibody, or a small molecule inhibitorof C1s, for example as described in Buerke et al. (J. Immunol.,167:5375-80 (2001).

In one embodiment, the compositions and methods of the invention areused in combination with one or more therapeutic regimens forsuppressing humoral rejection, including, without limitation, tacrolimusand mycophenolate mofetil therapy, immunoadsorption, intravenousimmunoglobulin therapy, and plasmapheresis.

5.22.1. Diagnosis and Clinical Criteria

The present invention provides antibodies, compositions and methods fortreating and preventing GVHD, humoral rejection, and post-transplantlymphoproliferative disorder in human transplant recipients. Thecompositions and methods of the invention can be used regardless of theparticular indications which gave rise to the need for a transplant.Similarly, the use of the compositions and methods of the invention forthe treatment and prevention of GVHD, humoral rejection, andpost-transplant lymphoproliferative disorders is not limited by theparticular type of tissue which is intended for transplantation or whichhas been transplanted.

In one embodiment, the invention provides compositions and methods forthe prevention of humoral rejection in a human transplant recipientwherein the transplant recipient is identified as a patient or patientpopulation at increased risk for developing a humoral rejection. Suchpatients may also be referred to as “sensitized.” The criteria for theidentification of sensitized patients is known to the skilledpractitioner. Such criteria may include, for example, patients havingdetectable levels of circulating antibodies against HLA antigens, e.g.,anti-HLA alloantibodies. Such criteria may also include patients whohave undergone previous transplantations, a pregnancy, or multiple bloodtransfusions. Patients who are at an increased risk for humoralrejection also include those having imperfect donor-recipient HLAmatching, and those transplantations which are ABO-incompatible.Sensitized individuals are preferred candidates for pretreatment orconditioning prior to transplantation. Sensitized individuals are alsopreferred candidates for post-transplantation maintenance regimens forthe prevention of humoral rejection.

In one embodiment, the antibodies, compositions, and methods of theinvention comprise or are used in combination with a therapeutic regimenfor the treatment of an acute or chronic rejection. In particularembodiments, the rejection is characterized as a Stage I, a Stage II, aStage III, or a Stage IV humoral rejection.

In one embodiment, the antibodies, compositions, and methods of theinvention comprise or are used in combination with a therapeutic regimenfor the treatment of an early stage humoral rejection. In particularembodiments, the early stage humoral rejection is a Stage I, II, or IIIrejection. Clinical indications of an early stage humoral rejection aredetermined according to the knowledge and skill in the art and mayinclude, for example, the development in the patient of circulatingdonor-specific anti-HLA antibodies, the presence of complement markersof antibody activity such as C4d and C3d deposits in graft biopsies, andthe presence of anti-HLA antibodies in graft biopsies. Other indicatorsof an early stage humoral rejection are known to the skilledpractitioner and may include, for example, the development ofanti-endothelial antibodies, especially anti-vimentin antibodies, andthe development of nonclassical MHC class I-related chain A (MICA)alloantibodies.

In one embodiment, the compositions and methods of the inventioncomprise or are used in combination with a therapeutic regimen for thetreatment of humoral rejection characterized in part by graftdysfunction. In particular embodiments, the patient or patientpopulation in need of treatment for humoral rejection is identifiedaccording to criteria known in the art for graft dysfunction. Examplesof such criteria for particular types of grafts are provided in thesections that follow. In other embodiments, the patient or patientpopulation in need of treatment for humoral rejection is identifiedaccording to other criteria that are particular to the type of tissuegraft, such as histological criteria. Examples of such criteria are alsoprovided in the sections that follow.

5.22.2. Bone Marrow Transplants

The compositions and methods of the invention are useful for treating orpreventing GVHD, humoral rejection, and post-transplantlymphoproliferative disorder in a bone marrow transplant recipient. Inone embodiment, the compositions and methods of the invention compriseor are used in combination with a pre-transplant conditioning regimen.

In one embodiment, the compositions and methods of the invention areused to deplete B cells from a bone marrow graft prior totransplantation. The graft may be from any suitable source, for example,cord blood stem cells, peripheral blood stem cells, or a bone marrowtap. Peripheral blood stem cells may be harvested from donor bloodfollowing a suitable conditioning regimen. Suitable regimens are knownin the art and may include, for example, administration of one or moreof the following to the donor prior to harvesting the donor blood:NEUPOGEN, cytokines such as GM-CSF, low dose chemotherapeutic regimens,and chemokine therapy. The graft may be either allogeneic or autologousto the transplant recipient. The graft may also be a xenograft.

The compositions and methods of the invention are useful in a number ofcontexts in which there is a hematopoietic indication for bone marrowtransplantation. In one embodiment, an autologous bone marrow graft isindicated for a B cell leukemia or lymphoma, preferably acutelymphoblastic leukemia (“ALL”) or non-Hodgkins lymphoma, and thecompositions and methods of the invention are used for the depletion ofresidual malignant cells contaminating the graft. In one embodiment, anautologous bone marrow transplant is indicated for patients unable toclear a viral infection, for example a viral infection associated withEpstein Barr virus (EBV), human immunodeficiency virus (HIV), orcytomegalovirus (CMV), and the anti-CD22 antibody compositions andmethods of the invention are used to deplete the graft of B cells whichmay harbor the virus. In another embodiment, the graft is an allogeneicgraft and the anti-CD22 antibody compositions and methods of theinvention are used for depleting donor B cells from the graft asprophylaxis against GVHD.

In one embodiment, the indication is a B cell associated autoimmunecondition and the compositions and methods of the invention are used todeplete the deleterious B cells from the patient without the need forchemotherapy or radiation therapy conditioning regimens. In oneembodiment, the compositions of the invention are administered incombination with a chemotherapy or radiation therapy regimen, whichregimen comprises a lower dose of one or more chemotherapeutic agents,or a lower dose of radiation, than the dose that is administered in theabsence of the compositions of the invention. In one embodiment, thepatient receives an autologous bone marrow graft subsequent tochemotherapy or radiation therapy, wherein the graft is depleted ofdeleterious B cells prior to transplantation using the compositions andmethods described herein.

A patient or patient population in need of, or likely to benefit from, abone marrow transplant is identified according to the knowledge andskill in the art. Examples of patients that may be candidates for bonemarrow transplantation include patients who have undergone chemotherapyor radiation therapy for the treatment of a cancer or an autoimmunedisease or disorder, and patients who are unable to clear a viralinfection residing in cells of the immune system.

5.22.3. Liver Transplants

The compositions and methods of the invention are useful for treating orpreventing GVHD, humoral rejection, and post-transplantlymphoproliferative disorder in a liver transplant recipient. Inparticular embodiments, the rejection is an acute or a chronicrejection. In one embodiment, the compositions and methods of theinvention are used for the prevention of GVHD, humoral rejection, andpost-transplant lymphoproliferative disorder in a liver transplantrecipient. In one embodiment, the compositions and methods of theinvention comprise or are used in combination with a pre-transplantconditioning regimen. In one embodiment, the compositions of theinvention are administered to the transplant recipient. In oneembodiment, the compositions of the invention are contacted with thegraft, ex vivo, prior to transplantation.

The liver transplant may be from any suitable source as determinedaccording to the knowledge and skill in the art. In one embodiment, theliver is an HLA-matched allogeneic graft. In another embodiment, theliver is a xenograft, preferably from a pig donor. In one embodiment,the liver is used ex vivo to filter the patient's blood, e.g.,extracorporeal perfusion. Extracorporeal perfusion is a form of liverdialysis in which the patient is surgically connected to a livermaintained outside the body. This procedure is sometimes referred to as“bioartificial liver.” In accordance with this embodiment, thecompositions and methods of the invention are used to prevent thedevelopment of antibodies against liver antigens which may contaminatethe patient's blood.

In one embodiment, the compositions and methods of the inventioncomprise an improved therapeutic regimen for the treatment andprevention of GVHD, humoral rejection, and post-transplantlymphoproliferative disorder. In a particular embodiment, thecompositions and methods of the invention comprise an improvedtherapeutic regimen, wherein the improvement lies in a decreasedincidence and/or severity of complications associated with traditionalimmunosuppressive agents. In one embodiment, the incidence and/orseverity of nephrotoxicity, hepatotoxicity, and hirsutism is reducedcompared with traditional regimens relying on cyclosporin A or othercalcinuerin inhibitors. In one embodiment, the incidence and/or severityof obesity, osteodystrophy, diabetes mellitus and susceptibility tobacterial and viral infections is reduced compared with traditionalregimens relying on corticosteroids.

In a preferred embodiment, the compositions and methods of the inventionare used in combination with lower doses of one or more traditionalimmunosuppressive agents than the doses that are used in the absence ofanti-lymphocyte antibody therapy. Preferably, the lower doses result ina decreased incidence and/or severity of one or more complicationsassociated with the one or more traditional immunosuppressive agents.

A patient or patient population in need of, or likely to benefit from, aliver transplant is identified according to the knowledge and skill inthe art. Examples of patients that may be candidates for livertransplantation include persons having one or more of the followingconditions, diseases, or disorders: acute liver failure, amyloidosis,bilirubin excretion disorders, biliary atresia, Budd-Chiari syndrome,chronic active autoimmune hepatitis, cirrhosis (either associated withviral hepatitis including hepatitis B and hepatitis C, alcoholiccirrhosis, or primary biliary cirrhosis), cholangitis, congenital factorVIII or IX disorder, copper metabolism disorders, cystic fibrosis,glycogenesis, hypercholesterolemia, lipidoses, mucopolysaccharidosis,primary sclerosing cholangitis, porphyrin metabolism disorders, purineand pyrimidine metabolism disorders, and primary benign and malignantneoplasms, especially of the liver and intrahepatic bile ducts, biliarysystem, biliary passages, or digestive system.

The clinical criteria for the identification of a patient or patientpopulation in need of, or likely to benefit from, a liver transplant canbe determined according to the knowledge and skill in the art. Suchcriteria may include, for example, one or more of the followingsymptoms: fatigue, weight loss, upper abdominal pain, purities,jaundice, liver enlargement, discolored urine, elevated alkalinephosphatase, and gamma glutamylpeptidase activity, elevated bilirubinlevels, decreased serum albumin, elevated liver-specific enzymes, lowbile production, increased blood urea nitrogen, increased creatinineand/or presence of anti-neutrophil cytoplasmic antibodies (ANCA) titers,recurrent variceal hemorrhage, intractable ascites, spontaneousbacterial peritonitis, refractory encephalopathy, severe jaundice,exacerbated synthetic dysfunction, sudden physiologic deterioration, andfulminant hepatic failure.

5.22.4. Kidney (Renal) Transplants

The compositions and methods of the invention are useful for treating orpreventing GVHD, humoral rejection, and post-transplantlymphoproliferative disorder in a renal transplant recipient. As usedherein, the term “renal transplant” encompasses the transplant of akidney and the combined transplant of a kidney and a pancreas. Inparticular embodiments, the rejection is characterized as an acuterejection or a chronic rejection.

In one embodiment, the compositions and methods of the inventioncomprise or are used in combination with a pre-transplant conditioningregimen. In one embodiment, a single dose of one or more of thecompositions of the present invention is effective to reduce panelreactive antibodies and deplete B cells in the patient or patientpopulation. In another embodiment, multiple doses of one or more of thecompositions of the invention are effective to reduce panel reactiveantibodies and deplete B cells in the patient or patient population. Inone embodiment, a single dose of one or more of the compositions of thepresent invention is administered in combination with one or moreimmunosuppressive agents and is effective to reduce panel reactiveantibodies and deplete B cells in the patient or patient population.

In certain embodiments, the compositions and methods of the inventionare for treating or preventing GVHD and graft rejection in a patienthaving received a renal transplant. In one embodiment, the patient hasnot yet exhibited clinical signs of rejection. In a related embodiment,the compositions and methods of the invention comprise or are used incombination with a maintenance regimen for the prevention of graftrejection in the transplant recipient. In one embodiment, thecompositions and methods of the invention are for the treatment of asubclinical humoral rejection. In a related embodiment, the patient orpatient population in need of treatment for a subclinical humoralrejection is indicated by the detection of Cd4 deposition in a biopsyfrom the graft or by the detection of circulating anti-HLA antibodies.

In one embodiment, the compositions and methods of the inventioncomprise or are used in combination with a therapeutic regimen for thetreatment of an acute or chronic rejection episode in a transplantrecipient. In one embodiment, the patient or patient population in needof treatment for an acute or chronic rejection episode is identified bythe detection of one or more clinical indicators of rejection. Inspecific embodiments, the one or more clinical indicators of rejectionare detected one to six weeks post-transplantation. In one embodiment,the one or more clinical indicators of rejection are detected 6, 12, 18,24, 36, 48, or 60 months post-transplantation. In a preferredembodiment, the acute rejection is biopsy-confirmed acute humoralrejection.

In one embodiment, one or more of the compositions of the inventioncomprise a therapeutic regimen for the treatment of acute rejection. Ina particular embodiment, the therapeutic regimen further comprises oneor more of the following: plasmapheresis, tacrolimus/mycophenolate,intravenous immunoglobulin, immunoadsorption with protein A, andanti-CD20 antibody. In one embodiment, the patient has been on animmunosuppressive protocol prior to the development of the rejection. Ina particular embodiment, the immunosuppressive protocol includes one ormore of cyclosporine, azathioprine, and steroid therapy.

Clinical indicators of acute humoral rejection are known in the art andinclude, for example, a sudden severe deterioration of renal function,the development of oliguria, and compromised renal perfusion. Additionalindicators include, for example, inflammatory cells in peritubularcapillaries on biopsy and circulating donor-specific alloantibodies. Inone embodiment, the patient presents with one or more of the followingdiagnostic criteria for a humoral rejection of a renal allograft: (1)morphological evidence of acute tissue injury; (2) evidence of antibodyaction, such as C4d deposits or immunoglobulin and complement inarterial fibrinoid necrosis; and (3) detectable circulating antibodiesagainst donor HLA antigens or donor endothelial antigens. In oneembodiment, the patient presents with all three of the above diagnosticcriteria.

In one embodiment, the patient presents with one or more of theforegoing diagnostic criteria of acute humoral rejection and thecompositions of the present invention are used in combination with oneor more of the following immunosuppressive agents to treat the acutehumoral rejection: intravenous immunoglobulin, anti-thymocyte globulins,anti-CD20 antibody, mycophenolate mofetil, or tacrolimus. In anotherembodiment, the compositions of the invention are used in combinationwith one or more immunosuppressive agents and a procedure for theremoval of alloantibodies from the patient, such as plasmapheresis orimmunoadsorption.

In one embodiment, the compositions and methods of the inventioncomprise or are used in combination with a therapeutic regimen for thetreatment of a chronic renal allograft rejection. In one embodiment, oneor more of the compositions of the invention are used alone or incombination with one or more immunosuppressive agents, including forexample, anti-CD154 (CD40L), tacrolimus, sirolimus, and mizoribin. In apreferred embodiment, one or more of the anti-CD22 antibodies of theinvention are used in combination with tacrolimus and mycophenolate.

Clinical indicators of chronic rejection in the kidneys are known in theart and may include, for example, arterial intimal fibrosis with intimalmononuclear cells (chronic allograft vasculopathy), duplication of theglomerular basement membranes (chronic allograft glomerulopathy),lamination of the peritubular basement membrane, C4d in peritubularcapillaries, and detectable circulating donor HLA-reactive antibodies.In a preferred embodiment, the compositions and methods of the inventioncomprise or are used in combination with a therapeutic regimen to treatchronic rejection before graft lesions develop.

In another embodiment, the patient or patient population in need oftreatment is identified as having one or more clinical indicators oftransplant glomerulopathy. In a related embodiment, the compositions ofthe invention comprise or are used in combination with a therapeuticregimen comprising one or more therapeutic agents. In a preferredembodiment, the therapeutic regimen is effective to stabilize renalfunction and inhibit graft rejection. In a particular embodiment, theone or more therapeutic agents include angiotensin converting enzyme(ACE) inhibitors and/or receptor antagonists, intravenousimmunoglobulin, anti-thymocyte globulins, anti-CD20 antibody,mycophenolate mofetil, or tacrolimus. Preferably, the anti-CD22antibodies of the invention are used in combination with mycophenolatemofetil and tacrolimus, with or without other therapeutic agents.Plasmapheresis may also be used as part of the therapeutic regimen.

A patient or patient population in need of, or likely to benefit from, arenal transplant is identified according to the knowledge and skill inthe art. Examples of patients that may be candidates for renaltransplantation include patients diagnosed with amyloidosis, diabetes(type I or type II), glomerular disease (e.g., glomerulonephritis),gout, hemolytic uremic syndrome, HIV, hereditary kidney disease (e.g.,polycystic kidney disease, congenital obstructive uropathy, cystinosis,or prune bell syndrome), other kidney disease (e.g., acquiredobstructive nephropathy, acute tubular necrosis, acute intersititialnephritis), rheumatoid arthritis, systemic lupus erythematosus, orsickle cell anemia. Other candidates for renal transplant includepatients having insulin deficiency, high blood pressure, severe injuryor burns, major surgery, heart disease or heart attack, liver disease orliver failure, vascular disease (e.g., progressive systemic sclerosis,renal artery thrombosis, scleroderma), vesicoureteral reflux, andcertain cancers (e.g., incidental carcinoma, lymphoma, multiple myeloma,renal cell carcinoma, Wilms tumor). Other candidates for renaltransplant may include, for example, heroin users, persons who haverejected a previous kidney or pancreas graft, and persons undergoing atherapeutic regimen comprising antibiotics, cyclosporin, orchemotherapy.

The clinical criteria for the identification of a patient or patientpopulation in need of, or likely to benefit from, a kidney transplantcan be determined according to the knowledge and skill in the art. Suchcriteria may include, for example, one or more of the following: urinaryproblems, bleeding, easy bruising, fatigue, confusion, nausea andvomiting, loss of appetite, pale skin (from anemia), pain in themuscles, joints, flanks, and chest, bone pain or fractures, and itching.

5.22.5. Cardiac Transplants

The compositions and methods of the invention are useful for treating orpreventing GVHD, humoral rejection, and post-transplantlymphoproliferative disorder in a cardiac transplant recipient. Inparticular embodiments, the rejection is an acute or a chronicrejection. In one embodiment, the compositions and methods of theinvention comprise or are used in combination with a pre-transplantconditioning regimen.

In certain embodiments, the compositions and methods of the inventioncomprise or are used in combination with a therapeutic regimen for thetreatment of acute humoral rejection in a cardiac transplant recipient.In a particular embodiment, the therapeutic regimen further comprisesone or more of the following: plasmapheresis, intravenousimmunoglobulin, and anti-CD20 antibody therapy. The patient or patientpopulation in need of treatment for an acute humoral rejection isidentified by the detection of one or more of the clinical indicationsof acute humoral rejection. Examples of clinical indicators of acutehumoral rejection may include one or more of the following: hemodynamicdysfunction, defined by shock, hypotension, decreased cardiac output,and a rise in capillary wedge or pulmonary artery pressure. In aparticular embodiment, the acute humoral rejection is diagnosed within6, 12, 18, 24, 36, 48, or 60 months post-transplantation.

In one embodiment, the compositions and methods of the inventioncomprise or are used in combination with a therapeutic regimen for theprevention of rejection in a cardiac transplant recipient. In oneembodiment, the transplant recipient in need of prophylaxis againstrejection is identified as a patient or patient population having one ormore of the following risk factors: female sex, cytomegalovirusseropositivity, elevated response to panel reactive antibodies, positivepre- and/or post-transplant crossmatch, and presensitization withimmunosuppressive agents.

In one embodiment, the compositions and methods of the invention are forthe treatment or prevention of graft deterioration in a heart transplantrecipient. In one embodiment, the transplant recipient in need oftreatment for, or prophylaxis against, graft deterioration is identifiedas a patient or patient population having one or more of the followingclinical indications of humoral rejection: deposition of immunoglobulin,C1q, C3, and/or C4d in capillaries, evidence of CD68-positive cellswithin capillaries, and evidence of infiltration of the graft byinflammatory cells upon biopsy. In one embodiment, the compositions ofthe present invention are used in combination with one or more of thefollowing immunosuppressive agents to treat graft deterioration in aheart transplant recipient: intravenous immunoglobulin, anti-thymocyteglobulins, anti-CD20 antibody, mycophenolate mofetil, or tacrolimus. Inanother embodiment, the anti-CD22 antibody compositions of the inventionare used in combination with one or more immunosuppressive agents and aprocedure for the removal of alloantibodies from the patient, such asplasmapheresis or immunoadsorption.

In one embodiment, the compositions and methods of the inventioncomprise or are used in combination with a therapeutic regimen for thetreatment of chronic cardiac rejection, preferably chronic allograftvasculopathy, also referred to as transplant coronary artery disease. Inanother embodiment, the compositions and methods of the inventioncomprise or are used in combination with a therapeutic regimen for theprevention of transplant coronary artery disease in a patient or patientpopulation at risk. The criteria for identifying a patient or patientpopulation at risk of developing transplant coronary artery disease areknown in the art and may include, for example, patients having poorlymatched transplants, patients who develop circulating anti-HLAantibodies, and patients who develop one or more clinical indications ofhumoral rejection early after cardiac transplant.

A patient or patient population in need of, or likely to benefit from, aheart transplant is identified according to the knowledge and skill inthe art. Examples of patients that may be candidates for hearttransplantation include those who have been diagnosed with any of thefollowing diseases and disorders: coronary artery disease,cardiomyopathy (noninflammatory disease of the heart), heart valvedisease with congestive heart failure, life-threatening abnormal heartrhythms that do not respond to other therapy, idiopathic cardiomyopathy,ischemic cardiomyopathy, dilated cardiomyopathy, ischemiccardiomyopathy, and congenital heart disease for which no conventionaltherapy exists or for which conventional therapy has failed.

The clinical criteria for the identification of a patient or patientpopulation in need of, or likely to benefit from, a heart transplant canbe determined according to the knowledge and skill in the art. Suchcriteria may include, for example, one or more of the following:ejection fraction less than 25%, intractable angina or malignant cardiacarrhythmias unresponsive to conventional therapy, and pulmonary vascularresistance of less than 2 Wood units. In addition, the patient orpatient population in need of a heart transplant may be identified byperforming a series of tests according to the knowledge and skill in theart. Such tests include, for example, resting and stressechocardiograms, EKG, assay of blood creatinine levels, coronaryarteriography, and cardiopulmonary evaluation including right- andleft-heart catheterization.

5.22.6. Lung Transplant

The compositions and methods of the invention are useful for treating orpreventing GVHD, humoral rejection, and post-transplantlymphoproliferative disorder in a lung transplant recipient. Inparticular embodiments, the rejection is characterized as an acute or achronic rejection. In one embodiment, the compositions and methods ofthe invention comprise or are used in combination with a pre-transplantconditioning regimen.

A patient or patient population in need of, or likely to benefit from, alung transplant is identified according to the knowledge and skill inthe art. Examples of patients that may be candidates for lungtransplantation include patients having one of the following diseases orconditions: bronchiectasis, chronic obstructive pulmonary disease,cystic fibrosis, Eisenmenger syndrome or congenital heart disease withEisenmenger syndrome. emphysema, eosinophilic granuloma of the lung, orhistiocytosis X, inhalation/burn trauma, lymphangioleiomyomatosis (LAM),primary pulmonary hypertension, pulmonary fibrosis (scarring of thelung), or sarcoidosis.

The clinical criteria for the identification of a patient or patientpopulation in need of, or likely to benefit from, a lung transplant canbe determined according to the knowledge and skill in the art. Suchcriteria may include, for example, one or more of the following: Chronicobstructive pulmonary disease (COPD) and alpha1-antitrypsin deficiencyemphysema characterized by one or more of the following indicators:postbronchodilator FEV1 of less than 25% predicted, resting hypoxemia,i.e., PaO₂ of less than 55-60 mm Hg, hypercapnia. secondary pulmonaryhypertension, a rapid rate of decline in FEV1, or life-threateningexacerbations; cystic fibrosis characterized by one or more of thefollowing indicators: postbronchodilator FEV1 of less than 30%predicted, resting hypoxemia, hypercapnia, or increasing frequency andseverity of exacerbations; idiopathic pulmonary fibrosis characterizedby one or more of the following indicators: vital capacity (VC) and TLCof less than 60-65% predicted, and resting hypoxemia; secondarypulmonary hypertension characterized by clinical, radiographic, orphysiologic progression while on medical therapy; primary pulmonaryhypertension characterized by one or more of the following indicators:NYHA functional class III or IV, mean right atrial pressure of greaterthan 10 mm Hg, mean pulmonary arterial pressure of greater than 50 mmHg, cardiac index of less than 2.5 L/min/m², and failure of therapy withlong-term prostacyclin infusion.

5.22.7. Post-Transplant Lymphoproliferative Disorder

The immunosuppression necessary for successful transplantation can giverise to a post-transplant lymphoproliferative disorder of B cell origin.Generally, a post-transplant lymphoproliferative disorder is associatedwith Epstein-Barr virus infected cells. Post-transplantlymphoproliferative disorder (PTLD) can range in severity from a benignself-limiting mononucleosis-like syndrome to an aggressive non-Hodgkinslymphoma. The compositions and methods of the present invention may beused to treat PTLD arising from any transplant. Preferably, thetransplant is a solid organ transplant, for example, a heart transplant,a liver transplant, a kidney transplant, or a combined kidney-pancreastransplant. In a preferred embodiment, the compositions and methods ofthe invention are used to treat PTLD as part of a therapeutic regimenthat includes a temporary cessation or reduction of otherimmunosuppressive therapy.

In one embodiment, the anti-CD22 antibody compositions of the inventionare administered as part of a therapeutic regimen including one or moreof the following: high dose intravenous gamma globulin, a cytokine, ananti-viral agent, and an anti-CD20 monoclonal antibody. Preferably, thetherapeutic regimen includes a temporary cessation or reduction ofimmunosuppression therapy. In a preferred embodiment, intravenous gammaglobulin is administered at a daily dose of 0.4 g/kg for 1 to 5 days,preferably for 3 days, and the cytokine is interferon alpha administeredfor at least 7 days. In one embodiment, one or more cytokines is used inthe regimen. In one embodiment, one or more anti-viral agents is used inthe regimen. The anti-viral agent may be selected from any suitableanti-viral agent known to those of skill in the art. In one embodiment,the anti-viral agent is aciclovir or ganciclovir. Preferably theanti-viral agent is administered for at least one or two weeks. Theanti-viral agent may also be administered for longer periods, forexample, I month, 2 months, 3 months, 4 months, or 5 months.

5.23. Patient Diagnosis and Therapeutic Regimens: Autoimmune Disease

According to certain aspects of the invention, the treatment regimen anddose used with the compositions and methods of the invention is chosenbased on a number of factors including, but not limited to, the stage ofthe autoimmune disease or disorder being treated. Appropriate treatmentregimens can be determined by one of skill in the art for particularstages of a autoimmune disease or disorder in a patient or patientpopulation. Dose response curves can be generated using standardprotocols in the art in order to determine the effective amount of thecompositions of the invention for treating patients having differentstages of a autoimmune disease or disorder. In general, patients havingmore activity of a autoimmune disease or disorder will require higherdoses and/or more frequent doses which may be administered over longerperiods of time in comparison to patients having less activity of anautoimmune disease or disorder.

The anti-CD22 antibodies, compositions and methods of the invention canbe practiced to treat an autoimmune disease or disorder. The term“autoimmune disease or disorder” refers to a condition in a subjectcharacterized by cellular, tissue and/or organ injury caused by animmunologic reaction of the subject to its own cells, tissues and/ororgans. The term “inflammatory disease” is used interchangeably with theterm “inflammatory disorder” to refer to a condition in a subjectcharacterized by inflammation, preferably chronic inflammation.Autoimmune disorders may or may not be associated with inflammation.Moreover, inflammation may or may not be caused by an autoimmunedisorder. Thus, certain disorders may be characterized as bothautoimmune and inflammatory disorders. Exemplary autoimmune diseases ordisorders include, but are not limited to: alopecia areata, ankylosingspondylitis, antiphospholipid syndrome, autoimmune Addison's disease,autoimmune diseases of the adrenal gland, autoimmune hemolytic anemia,autoimmune hepatitis, autoimmune oophoritis and orchitis, autoimmunethrombocytopenia, Behcet's disease, bullous pemphigoid, cardiomyopathy,celiac sprue-dermatitis, chronic fatigue immune dysfunction syndrome(CFIDS), chronic inflammatory demyelinating polyneuropathy,Churg-Strauss syndrome, cicatrical pemphigoid, CREST syndrome, coldagglutinin disease, Crohn's disease, discoid lupus, essential mixedcryoglobulinemia, diabetes, eosinophilic fascites,fibromyalgia-fibromyositis, glomerulonephritis, Graves' disease,Guillain-Barre, Hashimoto's thyroiditis, Henoch-Schönlein purpura,idiopathic pulmonary fibrosis, idiopathic/autoimmune thrombocytopeniapurpura (ITP), IgA neuropathy, juvenile arthritis, lichen planus, lupuserthematosus, Ménière's disease, mixed connective tissue disease,multiple sclerosis, type 1 or immune-mediated diabetes mellitus,myasthenia gravis, pemphigus-related disorders (e.g., pemphigusvulgaris), pernicious anemia, polyarteritis nodosa, polychrondritis,polyglandular syndromes, polymyalgia rheumatica, polymyositis anddermatomyositis, primary agammaglobulinemia, primary biliary cirrhosis,psoriasis, psoriatic arthritis, Raynauld's phenomenon, Reiter'ssyndrome, Rheumatoid arthritis, sarcoidosis, scleroderma, Sjögren'ssyndrome, stiff-man syndrome, systemic lupus erythematosis (SLE),Sweet's syndrome, Still's disease, lupus erythematosus, takayasuarteritis, temporal arteristis/giant cell arteritis, ulcerative colitis,uveitis, vasculitides such as dermatitis herpetiformis vasculitis,vitiligo, and Wegener's granulomatosis. Examples of inflammatorydisorders include, but are not limited to, asthma, encephilitis,inflammatory bowel disease, chronic obstructive pulmonary disease(COPD), allergic disorders, septic shock, pulmonary fibrosis,undifferentitated spondyloarthropathy, undifferentiated arthropathy,arthritis, inflammatory osteolysis, graft versus host disease,urticaria, Vogt-Koyanagi-Hareda syndrome and chronic inflammationresulting from chronic viral or bacteria infections.

CD22 is expressed on immature B cells, e.g. CD22 concomitantly with Igon the B cell surface. Therefore anti-CD22 mAb may be particularlysuited for depleting pre-B cells and immature B cells, e.g., in the bonemarrow.

5.23.1. Diagnosis of Autoimmune Diseases or Disorders

The diagnosis of an autoimmune disease or disorder is complicated inthat each type of autoimmune disease or disorder manifests differentlyamong patients. This heterogeneity of symptoms means that multiplefactors are typically used to arrive at a clinical diagnosis. Generally,clinicians use factors, such as, but not limited to, the presence ofautoantibodies, elevated cytokine levels, specific organ dysfunction,skin rashes, joint swelling, pain, bone remodeling, and/or loss ofmovement as primarily indicators of an autoimmune disease or disorder.For certain autoimmune diseases or disorders, such as RA and SLE,standards for diagnosis are known in the art. For certain autoimmunediseases or disorders, stages of disease have been characterized and arewell known in the art. These art recognized methods for diagnosingautoimmune diseases and disorders as well as stages of disease andscales of activity and/or severity of disease that are well known in theart can be used to identify patients and patient populations in need oftreatment for an autoimmune disease or disorder using the compositionsand methods of the invention.

5.23.2. Clinical Criteria for Diagnosing Autoimmune Diseases orDisorders

Diagnostic criteria for different autoimmune diseases or disorders areknown in the art. Historically, diagnosis is typically based on acombination of physical symptoms. More recently, molecular techniquessuch as gene-expression profiling have been applied to develop moleculardefinitions of autoimmune diseases or disorders. Exemplary methods forclinical diagnosis of particular autoimmune diseases or disorders areprovided below. Other suitable methods will be apparent to those skilledin the art.

In certain embodiments of the invention, patients with low levels ofautoimmune disease activity or patients with an early stage of anautoimmune disease (for diseases where stages are recognized) can beidentified for treatment using the anti-CD22 antibody compositions andmethods of the invention. The early diagnosis of autoimmune disease isdifficult due to the general symptoms and overlap of symptoms amongdiseases. In such embodiments, a patient treated at an early stage orwith low levels of an autoimmune disease activity has symptomscomprising at least one symptom of an autoimmune disease or disorder. Inrelated embodiments, a patient treated at an early stage or with lowlevels of an autoimmune disease has symptoms comprising at least 1, 2,3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, or 15 symptoms of an autoimmunedisease or disorder. The symptoms may be of any autoimmune diseases anddisorders or a combination thereof. Examples of autoimmune disease anddisorder symptoms are described below.

5.23.3. Rheumatoid Arthritis

Rheumatoid arthritis is a chronic disease, mainly characterized byinflammation of the lining, or synovium, of the joints. It can lead tolong-term joint damage, resulting in chronic pain, loss of function anddisability. Identifying patients or patient populations in need oftreatment for rheumatoid arthritis is a process. There is no definitivetest that provides a positive or negative diagnosis of rheumatoidarthritis. Clinicians rely on a number of tools including, medicalhistories, physical exams, lab tests, and X-rays.

Physical symptoms vary widely among patients and commonly include, butare not limited to, joint swelling, joint tenderness, loss of motion injoints, joint malalignment, bone remodeling, fatigue, stiffness(particularly in the morning and when sitting for long periods of time),weakness, flu-like symptoms (including a low-grade fever), painassociated with prolonged sitting, the occurrence of flares of diseaseactivity followed by remission or disease inactivity, rheumatoid nodulesor lumps of tissue under the skin (typically found on the elbows, theycan indicate more severe disease activity), muscle pain, loss ofappetite, depression, weight loss, anemia, cold and/or sweaty hands andfeet, and involvement of the glands around the eyes and mouth, causingdecreased production of tears and saliva (Sjögren's syndrome). ForSjogren's specifically, the following references may be used, Fox et al.Arthritis Rheum. (1986) 29:577-586, and Vitali et al. Ann. Rheum. Dis.(2002). 61:554-558.

Apart form physical symptoms, clinicians commonly use tests, such as,but not limited to, complete blood count, erythrocyte sedimentation rate(ESR or sed rate), C-reactive protein, rheumatoid factor, anti-DNAantibodies, antinuclear antibodies (ANA), anti-cardiolipin antibodies,imaging studies, radiographs (X-rays), magnetic resonance imaging (MRI)of joints or organs, joint ultrasound, bone scans, and bone densitometry(DEXA). These tests are examples of tests that can be used inconjunction with the compositions and methods of the invention to checkfor abnormalities that might exist (i.e., identify patients or patientpopulations in need of treatment) or to monitor side effects of drugsand check progress.

Early symptoms of rheumatoid arthritis commonly are found in the smallerjoints of the fingers, hands and wrists. Joint involvement is usuallysymmetrical, meaning that if a joint hurts on the left hand, the samejoint will hurt on the right hand. In general, more joint erosionindicates more severe disease activity.

Symptoms of more advanced disease activity include damage to cartilage,tendons, ligaments and bone, which causes deformity and instability inthe joints. The damage can lead to limited range of motion, resulting indaily tasks (grasping a fork, combing hair, buttoning a shirt) becomingmore difficult. Skin ulcers, greater susceptibility to infection, and ageneral decline in health are also indicators of more advanced diseaseactivity.

Progression of rheumatoid arthritis is commonly divided into threestages. The first stage is the swelling of the synovial lining, causingpain, warmth, stiffness, redness and swelling around the joint. Secondis the rapid division and growth of cells, or pannus, which causes thesynovium to thicken. In the third stage, the inflamed cells releaseenzymes that may digest bone and cartilage, often causing the involvedjoint to lose its shape and alignment, more pain, and loss of movement.

Molecular techniques can also be used to identify patients or patientpopulations in need of treatment. For example, rheumatoid arthritis hasbeen shown to be associated with allelic polymorphisms of the humanleukocyte antigen (HLA)-DR4 and HLA-DRB1 genes (Ollier and Winchester,1999, Genes and Genetics of Autoimmunity. Basel, Switzerland; Stastny,1978, N. Engl J Med 298:869-871; and Gregersen et al., 1987, ArthritisRheum 30:1205-1213). Rheumatoid arthritis patients frequently expresstwo disease-associated HLA-DRB1*04 alleles (Weyand et al., 1992 AnnIntern Med 117:801-806). Patients can be tested for allelicpolymorphisms using methods standard in the art. MHC genes are not theonly germline-encoded genes influencing susceptibility to RA that can beused to diagnose or identify patients or patient populations in need oftreatment. Female sex clearly increases the risk, and female patientsdevelop a different phenotype of the disease than do male patients. Anymolecular indicators of rheumatoid arthritis can be used to identifypatients or patient populations in need of treatment with the anti-CD22antibody compositions and methods of the invention.

Methods for determining activity of rheumatoid arthritis in a patient inrelation to a scale of activity are well known in the art and can beused in connection with the pharmaceutical compositions and methods ofthe invention. For example, the American College of RheumatologistsScore (ACR score) can be used to determine the activity of rheumatoidarthritis of a patient or a patient population. According to thismethod, patients are given a score that correlates to improvement. Forexample, patients with a 20% improvement in factors defined by the ACRwould be given an ACR20 score.

Initially, a patient exhibiting the symptoms of rheumatoid arthritis maybe treated with an analgesic. In other embodiments, a patient diagnosedwith or exhibiting the symptoms of rheumatoid arthritis is initiallytreated with nonsteroidal anti-inflammatory (NSAID) compounds. As thedisease progresses and/or the symptoms increase in severity, rheumatoidarthritis may be treated by the administration of steroids such as butnot limited to dexamethasone and prednisone. In more severe cases, achemotherapeutic agent, such as but not limited to methotrexate orcytoxin may be administered to relieve the symptoms of rheumatoidarthritis.

In certain instances, rheumatoid arthritis may be treated byadministration of gold, while in other instances a biologic, such as anantibody or a receptor (or receptor analog) may be administered.Examples of such therapeutic antibodies are RITUXIN and REMICADE. Anillustrative example of a soluble receptor that can be administered totreat rheumatoid arthritis is ENBREL.

In extremely severe cases of rheumatoid arthritis, surgery may beindicated. Surgical approaches may include, but not be limited to:synovectomy to reduce the amount of inflammatory tissue by removing thediseased synovium or lining of the joint; arthroscopic surgery to taketissue samples, remove loose cartilage, repair tears, smooth a roughsurface or remove diseased synovial tissue; osteotomy, meaning “to cutbone,” this procedure is used to increase stability by redistributingthe weight on the joint; joint replacement surgery or arthroplasty forthe surgical reconstruction or replacement of a joint; or arthrodesis orfusion to fuse two bones together.

In certain embodiments of the methods of invention, a patient can betreated with an anti-CD22 antibody prior, concurrent, or subsequent toany of the therapies disclosed above. Moreover, the anti-CD22 antibodiesof the present invention may be administered in combination with any ofthe analgesic, NSAID, steroid, or chemotherapeutic agents noted above,as well as in combination with a biologic administered for the treatmentof rheumatoid arthritis.

5.23.4. Systemic Lupus Erythematosis (SLE)

Systemic lupus erythematosis (SLE) is a chronic (long-lasting) rheumaticdisease which affects joints, muscles and other parts of the body.Patients or patient populations in need of treatment for SLE can beidentified by examining physical symptoms and/or laboratory testresults. Physical symptoms vary widely among patients. For example, inSLE, typically 4 of the following 11 symptoms exist before a patient isdiagnosed with SLE: 1) malar rash: rash over the cheeks; 2) discoidrash: red raised patches; 3) photosensitivity: reaction to sunlight,resulting in the development of or increase in skin rash; 4) oralulcers: ulcers in the nose or mouth, usually painless; 5) arthritis:nonerosive arthritis involving two or more peripheral joints (arthritisin which the bones around the joints do not become destroyed); 6)serositis pleuritis or pericarditis: (inflammation of the lining of thelung or heart); 7) renal disorder: excessive protein in the urine(greater than 0.5 gm/day or 3+ on test sticks) and/or cellular casts(abnormal elements the urine, derived from red and/or white cells and/orkidney tubule cells); 8) neurologic disorder: seizures (convulsions)and/or psychosis in the absence of drugs or metabolic disturbances whichare known to cause such effects; 9) hematologic disorder: hemolyticanemia or leukopenia (white blood count below 4,000 cells per cubicmillimeter) or lymphopenia (less than 1,500 lymphocytes per cubicmillimeter) or thrombocytopenia (less than 100,000 platelets per cubicmillimeter) (The leukopenia and lymphopenia must be detected on two ormore occasions. The thrombocytopenia must be detected in the absence ofdrugs known to induce it); 10) antinuclear antibody: positive test forantinuclear antibodies (ana) in the absence of drugs known to induce it;and/or 11) immunologic disorder: positive anti-double stranded anti-DNAtest, positive anti-sm test, positive antiphospholipid antibody such asanticardiolipin, or false positive syphilis test (vdrl).

Other physical symptoms that may be indicative of SLE include, but arenot limited to, anemia, fatigue, fever, skin rash, muscle aches, nausea,vomiting and diarrhea, swollen glands, lack of appetite, sensitivity tocold (Raynaud's phenomenon), and weight loss.

Laboratory tests can also be used to identify patients or patientpopulations in need of treatment. For example, a blood test can be usedto detect a autoantibodies found in the blood of almost all people withSLE. Such tests may include but are not limited to tests for antinuclearantibodies (ANA) in the absence of drugs known to induce it (Rahman, A.and Hiepe, F. Lupus. (2002). 11(12):770-773), anti-double strandedanti-DNA (Keren, D. F. Clin. Lab. Med. (2002) 22(2):447-474), anti-Sm,antiphospholipid antibody such as anticardiolipin (Gezer, S. Dis. Mon.2003. 49(12):696-741), or false positive syphilis tests (VDRL).

Other tests may include a complement test (C3, C4, CH50, CH100) can beused to measure the amount of complement proteins circulating in theblood (Manzi et al. Lupus 2004. 13(5):298-303), a sedimentation rate(ESR) or C-reactive protein (CRP) may be used to measure inflammationlevels, a urine analysis can be used to detect kidney problems, chestX-rays may be taken to detect lung damage, and an EKG can be used todetect heart problems.

Chronic SLE is associated with accumulating collateral damage toinvolved organ, particularly the kidney. Accordingly, early therapeuticintervention is desirable, i.e. prior to, for example, kidney failure.Available treatments for SLE are similar to those available forrheumatoid arthritis. These include initial treatments, either with ananalgesic or a nonsteroidal anti-inflammatory (NSAID) compound. As thedisease progresses and/or the symptoms increase in severity, SLE may betreated by the administration of steroids such as but not limited todexarnethasone and prednisone.

In more severe cases, a chemotherapeutic agent, such as but not limitedto methotrexate or cytoxin may be administered to relieve the symptomsof SLE. However, this approach is not preferred where the patient is afemale of child-bearing age. In such instances, those therapeuticapproaches that do not interfere with the reproductive capacity of thepatient are strongly preferred.

In certain instances, SLE may be treated by administration of abiologic, such as an antibody or a receptor (or receptor analog).Examples of such therapeutic antibodies are RITUXIN and REMICADE. Anillustrative example of a soluble receptor for an inflammatory cytokinethat can be administered to treat SLE is ENBREL.

In certain embodiments of the methods of invention, a patient can betreated with an anti-CD22 antibody prior, concurrent, or subsequent toany of the therapies disclosed above that are used for the treatment ofSLE. Moreover, the anti-CD22 antibodies of the present invention may beadministered in combination with any of the analgesic, NSAID, steroid,or chemotherapeutic agents noted above, as well as in combination with abiologic administered for the treatment of SLE.

5.23.5. Idiopathic/Autoimmune Thrombocytopenia Purpura (ITP)

Idiopathic/autoimmune thrombocytopenia purpura (ITP) is a disorder ofthe blood characterized by immunoglobulin G (IgG) autoantibodies thatinteract with platelet cells and result in the destruction of thoseplatelet cells. Typically, the antibodies are specific to plateletmembrane glycoproteins. The disorder may be acute (temporary, lastingless than 2 months) or chronic (persisting for longer than 6 months).Patients or patient populations in need of treatment for ITP can beidentified by examining a patient's medical history, physical symptoms,and/or laboratory test results. (Provan, D., and Newland, A., Br. J.Haematol. (2002) 118(4):933-944; George, J. N. Curr. Hematol. (2003)2(5):381-387; Karptkin, S. Autoimmunity. (2004) 37(4):363-368; Cines, D.B., and Blanchette, V. S., N. Engl. J. Med (2002) 346(13)995-1008).

Physical symptoms include purplish-looking areas of the skin and mucousmembranes (such as the lining of the mouth) where bleeding has occurredas a result of a decrease in the number of platelet cells. The mainsymptom is bleeding, which can include bruising (“ecchymosis”) and tinyred dots on the skin or mucous membranes (“petechiae”). In someinstances bleeding from the nose, gums, digestive or urinary tracts mayalso occur. Rarely, bleeding within the brain occurs. Common signs,symptoms, and precipitating factors also include, but are not limitedto, abrupt onset (childhood ITP), gradual onset (adult ITP), nonpalpablepetechiae, purpura, menorrhagia, epistaxis, gingival bleeding,hemorrhagic bullae on mucous membranes, signs of GI bleeding,menometrorrhagia, evidence of intracranial hemorrhage, nonpalpablespleen, retinal hemorrhages, recent live virus immunization (childhoodITP), recent viral illness (childhood ITP), spontaneous bleeding whenplatelet count is less than 20,000/mm³, and bruising tendency.

Laboratory test that can be used to diagnose ITP include, but are notlimited to, a complete blood count test, or a bone marrow examination toverify that there are adequate platelet-forming cells (megakaryocyte) inthe marrow and to rule out other diseases such as metastatic cancer andleukemia. Isolated thrombocytopenia is the key finding regardinglaboratory evaluation. Giant platelets on peripheral smear areindicative of congenital thrombocytopenia. A CT scan of the head may bewarranted if concern exists regarding intracranial hemorrhage.

The current treatments for ITP include, platelet transfusions andsplenectomy. Other treatments include, the administration ofglucocorticoids, administration of immunosuppressive agents,administration of agents that enhance platelet production, such asIL-11, and agents that activate megakaryocytes to produce platelets,such as thrombopoietin (TPO).

In more severe cases, a chemotherapeutic agent, such as but not limitedto vincristine and vinblastine may be administered to relieve thesymptoms of ITP. However, this approach is not preferred where thepatient is a female of child-bearing age. In such instances, thosetherapeutic approaches that do not interfere with the reproductivecapacity of the patient are strongly preferred.

In certain instances, ITP may be treated by administration of abiologic, such as an antibody or a receptor (or receptor analog).Examples of such therapeutic antibodies are anti-CD20 antibodies, suchas, Rituximab.

In certain embodiments of the methods of invention, a patient can betreated with an anti-CD22 antibody prior, concurrent, or subsequent toany of the therapies disclosed above that are used for the treatment ofITP. Moreover, the anti-CD22 antibodies of the present invention may beadministered in combination with any of the agents noted above, as wellas in combination with a biologic administered for the treatment of ITP.

5.23.6. Pemphigus and Pemphigoid-Related Disorders

Both pemphigus- and pemphigoid-related disorders are a heterogeneousgroup of autoimmune diseases characterized by a blistering condition ofthe skin and/or mucosal surfaces. In both diseases, the blistering iscaused by autoimmune antibodies that recognize various proteinsexpressed on the surface of epithelial cells in the dermis and/orepidermis.

In patients with pemphigus-related disease, the blistering occurs withinthe epidermis and is due to the binding of autoantibodies specific fordesmoglein 1 (Dsg1) and/or desmoglein 3 (Dsg3). The classic subtypes ofpemphigus can be distinguished according to anti-desmoglein antibodyspecificities. Patients with pemphigus foliaceus (PF) produce anti-Dsg1antibodies only. Patients with pemphigus vulgaris (PV) andparaneoplastic pemphigus (PNP) produce anti-Dsg3 antibodies if theirlesions are restricted to mucosal tissues. In contrast, PV and PNPpatients with lesions of the skin and mucosa produce both anti-Dsg1 and-Dsg3 autoantibodies. (Nagasaka, T., et al. J. Clin. Invest. 2004.114:1484-1492; Seishema, M., et al. Arch Dermatol. 2004.140(12):1500-1503; Amagai, M., J. Dermatol. Sci. 1999. 20(2):92-102)

In patients with pemphigoid-related disease including but not limitedto, bulous phemphigoid, urticarial bulous pemphigoid, cicatricialpemphigoid, epidermolysis bullosa acquisita, and Linear IgA bullousdermatosis, the blistering occurs at the interface of the dermis withthe epidermis. The most common form of pemphigoid disease is bulouspemphigoid (BP) which is characterized by the presence of autoantibodiesthat bind the bullous pemphigoid antigen 180 (BP180), bullous pemphigoidantigen 230 (BP230), laminin 5, and/or beta 4 integrin. (Fontao, L., etal. Mol. Biol. Cell. 2003) 14(5):1978-1992; Challacombe, S. J., et alActa Odontol. Scand. (2001). 59(4):226-234.)

Patients or patient populations in need of treatment for pemphigus- orpemphigoid-related disorders can be identified by examining a patient'smedical history, physical symptoms, and/or laboratory test results(reviewed in: Mutasim, D. F. Drugs Aging. (2003).20(9):663-681; Yeh, S.W. et al. Dermatol. Ther. (2003). 16(3):214-223; Rosenkrantz, W. S. Vet.Dermatol. 15(2):90-98).

Typically, diagnosis of these pemphigus- or pemphigoid-related disordersis made by skin biopsy. The biopsy skin sample is examinedmicroscopically to determine the anatomical site of the blister (e.g.epidermis or between dermis and epidermis). These findings arecorrelated with direct or indirect immunohistochemical analyses todetect the presence of autoantibodies at the site of the lesion. Serumsamples from patients may also be examined for the presence ofcirculating autoantibodies using an ELISA-based test for specificproteins. Several ELISA-based assays have been described for detectionof desmoglein antibodies in human samples (Hashimoto, T. Arch. Dermatol.Res. (2003) 295 Suppl. 1:S2-11). The presence of these desmogleinautoantibodies in biopsy samples is diagnostic of pemphigus.

Clinically, pemphigus vulgaris can be diagnosed by the presence ofblisters in the mouth. Inflammation or erosions may also be present inthe lining of the eye and eyelids, and the membranes of the nose orgenital tract. Half of the patients also develop blisters or erosions ofthe skin, often in the groin, underarm, face, scalp and chest areas.Pemphigus foliaceus is a superficial, relatively mild form of pemphigus.It usually manifests on the face and scalp, but also involves the backand chest. Lesions do not occur in the mouth. The blisters are moreconfined to the outermost surface and often itch. Paraneoplasticpemphigus is very rare and generally occurs in people who have cancer.The lesions are painful and affect the mouth, lips and esophagus(swallowing tube) as well as the skin. Due to involvement of theairways, signs of respiratory disease may occur and can belife-threatening.

The current treatments for pemphigus or pemphigoid-related diseaseincludes the topical administration of creams and ointments to alleviatethe discomfort associated with the skin condition, the administration ofanti-inflammatory agents or the administration of immunosuppressiveagents.

In certain embodiments of the methods of invention, a patient can betreated with an anti-CD22 antibody prior, concurrent, or subsequent toany of the therapies disclosed above that are used for the treatment ofpemphigoid or pemphigoid related disease. Moreover, the anti-CD22antibodies of the present invention may be administered in combinationwith any of the agents noted above.

5.23.7. Autoimmune Diabetes

According to certain aspects of the invention, a patient in need oftreatment for autoimmune diabetes, also known as type 1A diabetes, canbe treated with the anti-CD22 antibody compositions and methods of theinvention. Type 1A diabetes is an autoimmune disease caused by thesynergistic effects of genetic, environmental, and immunologic factorsthat ultimately destroy the pancreatic beta cells. The consequences ofpancreatic beta cell destruction is a decrease in beta cell mass,insulin production/secretion declines and blood glucose levels graduallyrise.

Patients or patient populations in need of treatment for type 1Adiabetes can be identified by examining a patient's medical history,physical symptoms, and/or laboratory test results. Symptoms often comeon suddenly and include, but are not limited to, low or non-existentblood insulin levels, increased thirst, increased urination, constanthunger, weight loss, blurred vision, and/or fatigue. Overt diabetes doesnot usually become evident until a majority of beta cells are destroyed(>80%). Typically, diabetes is clinically diagnosed if a patient has arandom (without regard to time since last meal) blood glucoseconcentration≧11.1 μmol/L (200 mg/dL) and/or a fasting (no caloricintake for at least 8 hours) plasma glucose≧7.0 mmol/L (126 mg/dI)and/or a two-hour plasma glucose≧11.1 mmol/L (200 mg/dL). Ideally, thesetests should be repeated on different days with comparable resultsbefore diagnosis is confirmed. (Harrison's Principles of InternalMedicine, 16^(th) ed./editors, Dennis L. Kasper, et al. The McGraw-HillCompanies, Inc. 2005 New York, N.Y.).

Although the precise etiology of type 1A diabetes is unknown, thereexists clear genetic linkage to specific HLA serotypes. In particular,autoimmune diabetes is associated with HLA DR3 and DR4 serotypes. Thepresence of both DR3 and DR4 confers the highest known genetic risk.Susceptibility to autoimmune diabetes is also linked to HLA class II(HLA-DQB1*0302. In contrast, HLA haplotypes with DRB1-1501 andDQA1-0102-DQB1-0602 are associated with protection from type 1A diabetes(Redondo, M. J., et al. J. Clin. Endocrinol. Metabolism (2000)10:3793-3797.)

The destruction of the insulin producing beta islet cells can beaccompanied by islet cell autoantibodies, activated lymphocyticinfiltrates in the pancreas and draining lymph nodes, T lymphocytesresponsive to islet cell proteins, and release of inflammatory cytokineswithin the islets (Harrison's Principles of Internal Medicine, 16^(th)ed./editors, Dennis L. Kasper, et al. The McGraw-Hill Companies, Inc.2005 New York, N.Y.).

Autoantibodies associated with type 1A diabetes include but are notlimited to antibodies that bind insulin, glutamic acid decarboxylase(GAD), ICA-512/IA-2, phogrin, islet ganglioside and carboxypeptidase H(Gianani, R. and Eisenbarth, G. S. Immunol. Rev. (2005) 204:232-249;Kelemen, K. et al, J. Immunol. (2004) 172(6):3955-3962); Falorni, A. andBorozzetti, A. Best Pract. Res. Clin. Endocrinol. Metab. 2005.19(1):119-133.)

The current treatments for autoimmune diabetes include theadministration of vitamin D, corticosteroids, agents which control bloodpressure and agents that control glycemia (blood sugar levels).

In certain embodiments of the methods of invention, a patient can betreated with an anti-CD22 antibody prior, concurrent, or subsequent toany of the therapies disclosed above that are used for the treatment ofautoimmune diabetes. Moreover, the anti-CD22 antibodies of the presentinvention may be administered in combination with any of the agentsnoted above.

5.23.8. Systemic Sclerosis (Scleroderma) and Related Disorders

Systemic sclerosis also known as Scleroderma encompasses a heterogeneousgroup of diseases including but not limited to, Limited cutaneousdisease, Diffuse cutaneous disease, Sine scleroderma, Undifferentiatedconnective tissue disease, Overlap syndromes, Localized scleroderma,Morphea, Linear scleroderma, En coup de saber, Scleredema adultorum ofBuschke, Scleromyxedema, Chronic graft-vs.-host disease, Eosinophilicfasciitis, Digital sclerosis in diabetes, and Primary anylooidosisandanyloidosis associated with multiple myeloma. (Reviewed in: Harrison'sPrinciples of Internal Medicine, 16^(th) ed./editors, Dennis L. Kasper,et al. The McGraw-Hill Companies, Inc. 2005 New York, N.Y.).

Clinical features associated with scleroderma can include Raynaud'sphenomenon, skin thickening, subcutaneious calcinosis, telangiectasia,arthralgias/arthritis, myopathy, esophageal dysmotility. pulmonaryfibrosis, isolated pulmonary arterial hypertension, congestive heartfailure and renal crisis. The extent to which an patient displays one ormore of these disease manifestations can influence the diagnosis andpotential treatment plan.

Autoantibodies include: Anti-topoisomerase 1, anticentromere, anti-RNApolymerase I, II, and/or III, anti-Th RNP, anti-U, RNP(anti-fibrillarin), anti-PM/Sci, anti-nuclear antibodies (ANA).

Identification of patients and patient populations in need of treatmentof scleroderma can be based on clinical history and physical findings.Patients or patient populations in need of treatment for scleroderma canbe identified by examining a patient's medical history, physicalsymptoms, and/or laboratory test results. Diagnosis may be delayed inpatients without significant skin thickening. Laboratory, X-ray,pulmonary function tests, and skin or renal (kidney) biopsies can beused to determine the extent and severity of internal organ involvement.

In the early months or years of disease onset, scleroderma may resemblemany other connective tissue diseases, such as, but not limited to,Systemic Lupus Erythematosus, Polymyositis, and Rheumatoid Arthritis.

The most classic symptom of systemic sclerosis (scleroderma) issclerodactyl). Initial symptoms include swollen hands, which sometimesprogress to this tapering and claw-like deformity. Not everyone withscleroderma develops this degree of skin hardening. Other symptoms caninclude morphea, linear sclerodactyl (hardened fingers), Raynaud'ssyndrome, calcinosis, and telangiectasia.

Blood tests such as anti-nuclear antibody (ANA) tests can be used in thediagnosis of both localized and systemic scleroderma. For example,anti-centromere antibodies (ACA) and anti-Scl-70 antibodies areindicative of patients in need of treatment for systemic sclerosis (Hoet al., 2003, Arthritis Res Ther. 5:80-93); anti-topo II alpha antibodyare indicative of patients in need of treatment for local scleroderma;and anti-topo I alpha antibody are indicative of patients in need oftreatment for systemic scleroderma. Several types of scleroderma andmethods for diagnosing these types are recognized and well known in theart, including, but not limited to, juvenile scleroderma (Foeldvari,Curr Opin Rheumatol 14:699-703 (2002); Cefle et al., Int J Clin Pract.58:635-638 (2004)); localized scleroderma; Nodular Scleroderma (Cannick,J. Rheumatol. 30:2500-2502 (2003)); and Systemic scleroderma, including,but not limited to, Calcinosis, Raynaud's, Esophagus, Sclerodactyl), andTelangiectasia (CREST), limited systemic scleroderma, and diffusesystemic scleroderma. Systemic scleroderma is also known as systemicsclerosis (SSc). It may also be referred to as Progressive SystemicSclerosis (PSSc), or Familial Progressive Systemic Sclerosis (FPSSc)(Nadashkevich et al., Med Sci Monit. 10:CR615-621 (2004); Frances etal., Rev Prat. 52:1884-90 (2002)). Systemic sclerosis is a multisystemdisorder characterized by the presence of connective tissue sclerosis,vascular abnormalities concerning small-sized arteries and themicrocirculation, and autoimmune changes.

The type of systemic scleroderma known as CREST is not characterized byany skin tightening. CREST is characterized by Calcinosis (calciumdeposits), usually in the fingers; Raynaud's; loss of muscle control ofthe Esophagus, which can cause difficulty swallowing; Sclerodactyl), atapering deformity of the bones of the fingers; and Telangiectasia,small red spots on the skin of the fingers, face, or inside of themouth. Typically two of these symptoms is sufficient for diagnosis ofCREST. CREST may occur alone, or in combination with any other form ofScleroderma or with other autoimmune diseases.

Limited Scleroderma is characterized by tight skin limited to thefingers, along with either pitting digital ulcers (secondary toRaynaud's) and/or lung fibrosis. The skin of the face and neck may alsobe involved in limited scleroderma.

Diffuse Scleroderma is diagnosed whenever there is proximal tight skin.Proximal means located closest to the reference point. Proximal tightskin can be skin tightness above the wrists or above the elbows.Typically, a patient with skin tightness only between their elbows andtheir wrists will receive a diagnosis of either diffuse or limitedsystemic Scleroderma, depending on which meaning of proximal thediagnosing clinician uses.

The current therapies for scleroderma include extracorporealphotophoresis following 6-methoxypsoralen, and autologous stem celltransplant,

The current treatments for scleroderma include the administration of thefollowing agents, penicillamine, cholchicine, interferon alpha,interpheron gamma, chlorambucil, cyclosporine, 5-fluorouracil,cyclophosphamide, minocycline, thalidomide, etanercept, or methotrexate.

5.24. Determining CD22 Density in a Sample or Subject

While not required, assays for CD22 density can be employed to furthercharacterize the patient's diagnosis. Methods of determining the densityof antibody binding to cells are known to those skilled in the art (See,e.g., Sato et al., J. Immunology 165:6635-6643 (2000); which discloses amethod of assessing cell surface density of specific CD antigens). Otherstandard methods include Scatchard analysis. For example, the antibodyor fragment can be isolated, radiolabeled, and the specific activity ofthe radiolabeled antibody determined. The antibody is then contactedwith a target cell expressing CD22. The radioactivity associated withthe cell can be measured and, based on the specific activity, the amountof antibody or antibody fragment bound to the cell determined.

Alternatively, fluorescence activated cell sorting (FACS) analysis canbe employed. Generally, the antibody or antibody fragment is bound to atarget cell expressing CD22. A second reagent that binds to the antibodyis then added, for example, a fluorochrome labeled anti-immunoglobulinantibody. Fluorochrome staining can then be measured and used todetermine the density of antibody or antibody fragment binding to thecell.

As another suitable method, the antibody or antibody fragment can bedirectly labeled with a detectable label, such as a fluorophore, andbound to a target cell. The ratio of label to protein is determined andcompared with standard beads with known amounts of label bound thereto.Comparison of the amount of label bound to the cell with the knownstandards can be used to calculate the amount of antibody bound to thecell.

In yet another aspect, the present invention provides a method fordetecting in vitro or in vivo the presence and/or density of CD22 in asample or individual. This can also be useful for monitoring disease andeffect of treatment and for determining and adjusting the dose of theantibody to be administered. The in vivo method can be performed usingimaging techniques such as PET (positron emission tomography) or SPECT(single photon emission computed tomography). Alternatively, one couldlabel the anti-CD22 antibody with Indium using a covalently attachedchelator. The resulting antibody can be imaged using standard gammacameras the same way as ZEVALIN™ (Indium labeled anti-CD20 mAb) (BiogenIdec, Cambridge Mass.) is used to image CD20 antigen.

In one embodiment, the in vivo method can be performed by contacting asample to be tested, optionally along with a control sample, with ahuman anti-CD22 antibody of the invention under conditions that allowfor formation of a complex between an antibody of the invention and thehuman CD22 antigen. Complex formation is then detected (e.g., using anFACS analysis or Western blotting). When using a control sample alongwith the test sample, a complex is detected in both samples and anystatistically significant difference in the formation of complexesbetween the samples is indicative of the presence of human CD22 in thetest sample.

In other embodiments, mean fluorescence intensity can be used as ameasure of CD22 density. In such embodiments, B cells are removed from apatient and stained with CD22 antibodies that have been labeled with afluorescent label and the fluorescence intensity is measured using flowcytometry. Fluorescence intensities can be measured and expressed as anaverage of intensity per B cell. Using such methods, mean florescenceintensities that are representative of CD22 density can be compared fora patient before and after treatment using the methods and compositionsof the invention, or between patients and normal levels of hCD22 on Bcells.

In patients where the density of CD22 expression on B cells has beendetermined, the density of CD22 may influence the determination and/oradjustment of the dosage and/or treatment regimen used with theanti-CD22 antibody of the compositions and methods of the invention. Forexample, where density of CD22 is high, it may be possible to useanti-CD22 antibodies that less efficiently mediate ADCC in humans. Incertain embodiments, where the patient treated using the compositionsand methods of the invention has a low CD22 density, a higher dosage ofthe anti-CD22 antibody of the compositions and methods of the inventionmay be used. In other embodiments, where the patient treated using thecompositions and methods of the invention has a low CD22 density, a lowdosage of the anti-CD22 antibody of the compositions and methods of theinvention may be used. In certain embodiments, where the patient treatedusing the compositions and methods of the invention has a high CD22density, a lower dosage of the anti-CD22 antibody of the compositionsand methods of the invention may be used. In certain embodiments, CD22density can be compared to CD20 density in a patient, CD22 density canbe compared to an average CD22 density for humans or for a particularpatient population, or CD22 density can be compared to CD22 levels inthe patient prior to therapy or prior to onset of a B cell disease ordisorder. In certain embodiments, the patient treated using thecompositions and methods of the invention has a B cell malignancy whereCD22 is present on the surface of B cells.

5.25. Immunotherapeutic Protocols

The anti-CD22 antibody compositions used in the therapeuticregimen/protocols, referred to herein as “anti-CD22 immunotherapy” canbe naked antibodies, immunoconjugates and/or fusion proteins. Thecompositions of the invention can be used as a single agent therapy orin combination with other therapeutic agents or regimens. The anti-CD22antibodies or immunoconjugates can be administered prior to,concurrently with, or following the administration of one or moretherapeutic agents. Therapeutic agents that can be used in combinationtherapeutic regimens with the compositions of the invention include anysubstance that inhibits or prevents the function of cells and/or causesdestruction of cells. Examples, include, but are not limited to,radioactive isotopes, chemotherapeutic agents, and toxins such asenzymatically active toxins of bacterial, fungal, plant or animalorigin, or fragments thereof.

The therapeutic regimens described herein, or any desired treatmentregimen can be tested for efficacy using the transgenic animal model,such as the mouse model described below, which expresses human CD22antigen in place of native CD22 antigen. Thus, an anti-CD22 antibodytreatment regimen can be tested in an animal model to determine efficacybefore administration to a human.

The anti-CD22 antibodies, compositions and methods of the invention canbe practiced to treat B cell diseases, including B cell malignancies.The term “B cell malignancy” includes any malignancy that is derivedfrom a cell of the B cell lineage. Exemplary B cell malignanciesinclude, but are not limited to: B cell subtype non-Hodgkin's lymphoma(NHL) including low grade/follicular, NHL, small lymphocytic (SL) NHL,intermediate grade/follicular NHL, intermediate grade diffuse NHL, highgrade immunoblastic NHL, high grade lymphoblastic NHL, high grade smallnon-cleaved cell NHL; mantle-cell lymphoma, and bulky disease NHL;Burkitt's lymphoma; multiple myeloma; pre-B acute lymphoblastic leukemiaand other malignancies that derive from early B cell precursors; commonacute lymphocytic leukemia (ALL); chronic lymphocytic leukemia (CLL)including immunoglobulin-mutated CLL and immunoglobulin-unmutated CLL;hairy cell leukemia; Null-acute lymphoblastic leukemia; Waldenström'sMacroglobulinemia; diffuse large B cell lymphoma (DLBCL) includinggerminal center B cell-like (GCB) DLBCL, activated B cell-like (ABC)DLBCL, and type 3 DLBCL; pro-lymphocytic leukemia; light chain disease;plasmacytoma; osteosclerotic myeloma; plasma cell leukemia; monoclonalgammopathy of undetermined significance (MGUS); smoldering multiplemyeloma (SMM); indolent multiple myeloma (IMM); Hodgkin's lymphomaincluding classical and nodular lymphocyte pre-dominant type;lymphoplasmacytic lymphoma (LPL); and marginal-zone lymphoma includinggastric mucosal-associated lymphoid tissue (MALT) lymphoma.

In one aspect of the invention, the inventive antibodies andcompositions disclosed herein can deplete mature B cells. Thus, asanother aspect, the invention can be employed to treat mature B cellmalignancies (i.e., express Ig on the cell surface) including but notlimited to follicular lymphoma, mantle-cell lymphoma, Burkitt'slymphoma, multiple myeloma, diffuse large B-cell lymphoma (DLBCL)including germinal center B cell-like (GCB) DLBCL, activated B cell-like(ABC) DLBCL, and type 3 DLBCL, Hodgkin's lymphoma including classicaland nodular lymphocyte pre-dominant type, lymphoplasmacytic lymphoma(LPL), marginal-zone lymphoma including gastric mucosal-associatedlymphoid tissue (MALT) lymphoma, and chronic lymphocytic leukemia (CLL)including immunoglobulin-mutated CLL and immunoglobulin-unmutated CLL.

Further, CD22 is expressed earlier in B cell development than, forexample, CD20, and is therefore particularly suited for treating pre-Bcell and immature B cell malignancies (i.e., do not express Ig on thecell surface), for example, in the bone marrow. Illustrative pre-B celland immature B cell malignancies include but are not limited to acutelymphoblastic leukemia

In other particular embodiments, the invention can be practiced to treatextranodal tumors.

5.26. Anti-CD22 Immunotherapy

In accordance with the present invention “anti-CD22 immunotherapy”encompasses the administration of any of the anti-CD22 antibodies of theinvention in accordance with any of the therapeutic regimens describedherein or known in the art. The anti-CD22 antibodies can be administeredas a naked antibodies, or immunoconjugates or fusion proteins.

Anti-CD22 immunotherapy encompasses the administration of the anti-CD22antibody as a single agent therapeutic for the treatment of a B cellmalignancy. Anti-CD22 immunotherapy encompasses methods of treating anearly stage disease resulting from a B cell malignancy. Anti-CD22immunotherapy encompasses methods of treating a B cell malignancywherein the anti-CD22 antibody mediates ADCC and/or apoptosis. Anti-CD22immunotherapy encompasses methods of treating a B cell malignancywherein the anti-CD22 antibody is administered before the patient hasreceived any treatment for the malignancy, whether that therapy ischemotherapy, radio chemical based therapy or surgical therapy.

In a preferred embodiment, a human subject having a B cell malignancycan be treated by administering a human or humanized antibody thatpreferably mediates human ADCC and/or apoptosis. In cases of early stagedisease, or single agent therapies, any anti-CD22 antibody thatpreferably mediates ADCC and/or apoptosis can be used in the humansubjects (including murine and chimeric antibodies); however, human andhumanized antibodies are preferred.

Antibodies of IgG1 or IgG3 human isotypes are preferred for therapy.However, the IgG2 or IgG4 human isotypes can be used, provided theymediate human ADCC and/or apoptosis. Such effector function can beassessed by measuring the ability of the antibody in question to mediatetarget cell lysis by effector cells or to induce or modulate apoptosisin target cells in vitro or in vivo.

The dose of antibody used should be sufficient to deplete circulating Bcells. Progress of the therapy can be monitored in the patient byanalyzing blood samples. Other signs of clinical improvement can be usedto monitor therapy.

Methods for measuring depletion of B cells that can be used inconnection with the compositions and methods of the invention are willknown in the art and include, but are not limited to the followingembodiments. In one embodiment, circulating B cells depletion can bemeasured with flow cytometry using a reagent other than an anti-CD22antibody that binds to B cells to define the amount of B cells. In otherembodiments, B cell levels in the blood can be monitored using standardserum analysis. In such embodiments, B cell depletion is indirectlymeasured by defining the amount to an antibody known to be produced by Bcells. The level of that antibody is then monitored to determine thedepletion and/or functional depletion of B cells. In another embodiment,B cell depletion can be measured by immunochemical staining to identifyB cells. In such embodiments, B cells or tissues or serum comprising Bcells extracted from a patient can be placed on microscope slides,labeled and examined for presence or absence. In related embodiments, acomparison is made between B cells extracted prior to therapy and afterto determine differences in the presence of B cells.

Tumor burden can be measured and used in connection with thecompositions and methods of the invention. Methods for measuring tumorburden are will known in the art and include, but are not limited to thefollowing embodiments. In certain embodiments, PET scans can be used tomeasure metabolic activity and identify areas of higher activity whichare indicative of tumors. CT scans and MRI can also be used to examinesoft tissue for the presence and size of tumors. In other embodiments,bone scan can be sued to measure tumor volume and location. In yet otherembodiments, tumor burden can be measured by examining the blood flowinto and out of a tumor using doppler technology (e.g., ultrasound). Insuch embodiments, changes in blood flow over time or deviations fromnormal blood flow in the appropriate tissue of a patient can be used tocalculate an estimate to tumor burden. Such methods for measuring tumorburden can be used prior to and following the methods of treatment ofthe invention.

In preferred embodiments of the methods of the invention B cells aredepleted and/or tumor burden is decreased while ADCC function ismaintained.

In embodiments of the invention where the anti-CD22 antibody isadministered as a single agent therapy, the invention contemplates useof different treatment regimens.

According to certain aspects of the invention, the anti-CD22 antibodyused in the compositions and methods of the invention, is a nakedantibody. In related embodiments, the dose of naked anti-CD22 antibodyused is at least about 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1,1.5, 2, 2.5, 3, 3.5, 4, 4.5, 5, 5.5, 6, 6.5, 7, 7.5, 8, 8.5, 9, 9.5, 10,10.5, 11, 11.5, 12, 12.5, 13, 13.5, 14, 14.5, 15, 15.5, 16, 16.5, 17,17.5, 18, 18.5, 19, 19.5, 20, 20.5, 25, 30, 35, 40, 45, or 50 mg/kg ofbody weight of a patient. In certain embodiments, the dose of nakedanti-CD22 antibody used is at least about 1 to 10, 5 to 15, 10 to 20, or15 to 25 mg/kg of body weight of a patient. In certain embodiments, thedose of naked anti-CD22 antibody used is at least about 1 to 20, 3 to15, or 5 to 10 mg/kg of body weight of a patient. In preferredembodiments, the dose of naked anti-CD22 antibody used is at least about5, 6, 7, 8, 9, or 10 mg/kg of body weight of a patient.

In certain embodiments, the dose of naked anti-CD22 antibody used is atleast about 25, 50, 75, 100, 125, 150, 175, 200, 225, 250, 275, 300,325, 350, 375, 400, 425, 450, 475, or 500 mg/m². In other embodiments,the dose of naked anti-CD22 antibody used is at least about 1, 5, 10,15, 20, 25, 50, 75, 100, 125, 150, 175, 200, 225, 250, 275, 300, 325,350, 375, 400, 425, 450, 475, or 500 mg per administration.

In certain embodiments, the dose comprises about 375 mg/m² of anti-CD22antibody administered weekly for 4 to 8 consecutive weeks. In certainembodiments, the dose is at least about 1, 2, 3, 4, 5, 6, 7, 8, 9, 10,11, 12, 13, 14, or 15 mg/kg of body weight of the patient administeredweekly for 4 to 8 consecutive weeks.

The exemplary doses of anti-CD22 antibody described above can beadministered as described in Section 5.20.3. In one embodiment, theabove doses are single dose injections. In other embodiments, the dosesare administered over a period of time. In other embodiments, the dosesare administered multiple times over a period of time. The period oftime may be measured in days, weeks, or months. Multiple doses of theanti-CD22 antibody can be administered at intervals suitable to achievea therapeutic benefit while balancing toxic side effects. For example,where multiple doses are used, it is preferred to time the intervals toallow for recovery of the patient's monocyte count prior to the repeattreatment with antibody. This dosing regimen will optimize theefficiency of treatment, since the monocyte population reflects ADCCfunction in the patient.

In certain embodiments, the compositions of the invention areadministered to a human patient as long as the patient in responsive totherapy. In other embodiments, the compositions of the invention areadministered to a human patient as long as the patient's disease doesnot progress. In related embodiments, the compositions of the inventionare administered to a human patient until a patient's disease does notprogress or has not progressed for a period of time, then the patient isnot administered the compositions of the invention unless the diseasereoccurs or begins to progress again. For example, a patient can betreated with any of the above doses for about 4 to 8 weeks, during whichtime the patient is monitored for disease progression. If diseaseprogression stops or reverses, then he patient will not be administeredthe compositions of the invention until that patient relapses, i.e., thedisease being treated reoccurs or progresses. Upon this reoccurrence orprogression, the patient can be treated again with the same dosingregimen initially used or using other doses described above.

In certain embodiments, the compositions of the invention can beadministered as a loading dose followed by multiple lower doses(maintenance doses) over a period of time. In such embodiments, thedoses may be timed and the amount adjusted to maintain effective B celldepletion. In preferred embodiments, the loading dose is about 10, 11,12, 13, 14, 15, 16, 17, or 18 mg/kg of patient body weight and themaintenance dose is at least about 5 to 10 mg/kg of patient body weight.In preferred embodiments, the maintenance dose is administered atintervals of every 7, 10, 14 or 21 days. The maintenance doses can becontinued indefinitely, until toxicity is present, until platelet countdecreases, until there is no disease progression, until the patientexhibits immunogenicity, or until disease progresses to a terminalstate. In yet other embodiments, the compositions of the invention areadministered to a human patient until the disease progresses to aterminal stage.

In embodiments of the invention where circulating monocyte levels of apatient are monitored as part of a treatment regimen, doses of anti-CD22antibody administered may be spaced to allow for recovery of monocytecount. For example, a composition of the invention may be administeredat intervals of every 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20,21, 22, 23, 24, 25, 26, 27, 28, 29, or 30 days.

In embodiments of the invention where an anti-CD22 antibody isconjugated to or administered in conjunction with a toxin, one skilledin the art will appreciate that the dose of anti-CD22 antibody can beadjusted based on the toxin dose and that the toxin dose will depend onthe specific type of toxin being used. Typically, where a toxin is used,the dose of anti-CD22 antibody will be less than the dose used with anaked anti-CD22 antibody. The appropriate dose can be determined for aparticular toxin using techniques well known in the art. For example, adose ranging study can be conducted to determine the maximum tolerateddose of anti-CD22 antibody when administered with or conjugated to atoxin.

In embodiments of the invention where an anti-CD22 antibody isconjugated to or administered in conjunction with a radiotherapeuticagent, the dose of the anti-CD22 antibody will vary depending on theradiotherapeutic used. In certain preferred embodiments, a two stepprocess is used. First, the human patient is administered a compositioncomprising a naked anti-CD22 antibody and about 6, 7, 8, 9, or 10 dayslater a small amount of the radiotherapeutic is administered. Second,once the tolerance, distribution, and clearance of the low dose therapyhas been determined, the patient is administered a dose of the nakedanti-CD22 antibody followed by a therapeutic amount of theradiotherapeutic is administered. Such treatment regimens are similar tothose approved for treatment of Non-Hodgkin's lymphoma using ZEVALIN™(Indium labeled anti-CD20 mAb) (Biogen Idec) or BEXXAR™ (GSK, CoulterPharmaceutical).

5.27. Combination with Chemotherapeutic Agents

Anti-CD22 immunotherapy (using naked antibody, immunoconjugates, orfusion proteins) can be used in conjunction with other therapiesincluding but not limited to, chemotherapy, radioimmunotherapy (RIT),chemotherapy and external beam radiation (combined modality therapy,CMT), or combined modality radioimmunotherapy (CMRIT) alone or incombination, etc. In certain preferred embodiments, the anti-CD22antibody therapy of the present invention can be administered inconjunction with CHOP (Cyclophosphamide-Hydroxydoxorubicin-Oncovin(vincristine)-Prednisolone), the most common chemotherapy regimen fortreating non-Hodgkin's lymphoma. As used herein, the term “administeredin conjunction with” means that the anti-CD22 immunotherapy can beadministered before, during, or subsequent to the other therapyemployed.

In certain embodiments, the anti-CD22 immunotherapy is in conjunctionwith a cytotoxic radionuclide or radiotherapeutic isotope. For example,an alpha-emitting isotope such as ²²⁵Ac, ²²⁴Ac, ²¹¹At, ²¹²Bi, ²¹³Bi,²¹²Pb, ²²⁴Ra, or ²²³Ra. Alternatively, the cytotoxic radionuclide may abeta-emitting isotope such as ¹⁸⁶Re, ¹⁸⁸Re, ⁹⁰Y, ¹³¹I, ⁶⁷Cu, ¹⁷⁷Lu,¹⁵³Sm, ¹⁶⁶Ho, or ⁶⁴Cu. Further, the cytotoxic radionuclide may emitAuger and low energy electrons and include the isotopes ¹²⁵I, ¹²³I, or⁷⁷Br. In other embodiments the isotope may be ¹⁹⁸Au, ³²P, and the like.In certain embodiments, the amount of the radionuclide administered tothe subject is between about 0.001 mCi/kg and about 10 mCi/kg.

In some preferred embodiments, the amount of the radionuclideadministered to the subject is between about 0.1 mCi/kg and about 1.0mCi/kg. In other preferred embodiments, the amount of the radionuclideadministered to the subject is between about 0.005 mCi/kg and 0.1mCi/kg.

In certain embodiments, the anti-CD22 immunotherapy is in conjunctionwith a chemical toxin or chemotherapeutic agent. Preferably the chemicaltoxin or chemotherapeutic agent is selected from the group consisting ofan enediyne such as calicheamicin and esperamicin; duocarmycin,methotrexate, doxorubicin, melphalan, chlorambucil, ARA-C, vindesine,mitomycin C, cis-platinum, etoposide, bleomycin and 5-fluorouracil.

Suitable chemical toxins or chemotherapeutic agents that can be used incombination therapies with the anti-CD22 immunotherapy include membersof the enediyne family of molecules, such as calicheamicin andesperamicin. Chemical toxins can also be taken from the group consistingof duocarmycin (see, e.g., U.S. Pat. No. 5,703,080 and U.S. Pat. No.4,923,990), methotrexate, doxorubicin, melphalan, chlorambucil, ARA-C,vindesine, mitomycin C, cis-platinum, etoposide, bleomycin and5-fluorouracil. Examples of chemotherapeutic agents also includeadriamycin, doxorubicin, 5-fluorouracil, cytosine arabinoside (“Ara-C”),cyclophosphamide, thiotepa, taxotere (docetaxel), busulfan, cytoxin,taxol, methotrexate, cisplatin, melphalan, vinblastine, bleomycin,etoposide, ifosfamide, mitomycin C, mitoxantrone, vincreistine,vinorelbine, carboplatin, teniposide, daunomycin, caminomycin,aminopterin, dactinomycin, mitomycins, esperamicins (see, U.S. Pat. No.4,675,187), melphalan and other related nitrogen mustards.

In other embodiments, for example, “CVB” (1.5 g/m² cyclophosphamide,200-400 mg/m² etoposide, and 150-200 mg/m² carmustine) can be used inthe combination therapies of the invention. CVB is a regimen used totreat non-Hodgkin's lymphoma. Patti et al., Eur. J. Haematol. 51:18(1993). Other suitable combination chemotherapeutic regimens arewell-known to those of skill in the art. See, for example, Freedman etal., “Non-Hodgkin's Lymphomas,” in CANCER MEDICINE, VOLUME 2, 3rdEdition, Holland et al. (eds.), pp. 2028-2068 (Lea & Febiger 1993). Asan illustration, first generation chemotherapeutic regimens fortreatment of intermediate-grade non-Hodgkin's lymphoma include C-MOPP(cyclophosphamide, vincristine, procarbazine and prednisone) and CHOP(cyclophosphamide, doxorubicin, vincristine, and prednisone). A usefulsecond generation chemotherapeutic regimen is m-BACOD (methotrexate,bleomycin, doxorubicin, cyclophosphamide, vincristine, dexamethasone andleucovorin), while a suitable third generation regimen is MACOP-B(methotrexate, doxorubicin, cyclophosphamide, vincristine, prednisone,bleomycin and leucovorin). Additional useful drugs include phenylbutyrate and brostatin-1. In a preferred multimodal therapy, bothchemotherapeutic drugs and cytokines are co-administered with anantibody, immunoconjugate or fusion protein according to the presentinvention. The cytokines, chemotherapeutic drugs and antibody,immunoconjugate or fusion protein can be administered in any order, ortogether.

Other toxins that are preferred for use in the compositions and methodsof the invention include poisonous lectins, plant toxins such as ricin,abrin, modeccin, botulina and diphtheria toxins. Of course, combinationsof the various toxins could also be coupled to one antibody moleculethereby accommodating variable cytotoxicity. Illustrative of toxinswhich are suitably employed in the combination therapies of theinvention are ricin, abrin, ribonuclease, DNase I, Staphylococcalenterotoxin-A, pokeweed antiviral protein, gelonin, diphtherin toxin,Pseudomonas exotoxin, and Pseudomonas endotoxin. See, for example,Pastan et al., Cell 47:641 (1986), and Goldenberg et al., Cancer Journalfor Clinicians 44:43 (1994). Enzymatically active toxins and fragmentsthereof which can be used include diphtheria A chain, nonbinding activefragments of diphtheria toxin, exotoxin A chain (from Pseudomonasaeruginosa), ricin A chain, abrin A chain, modeccin A chain,alpha-sarcin, Aleurites fordii proteins, dianthin proteins, Phytolacaamericana proteins (PAPI, PAPII, and PAP-S), momordica charantiainhibitor, curcin, crotin, sapaonaria officinalis inhibitor, gelonin,mitogellin, restrictocin, phenomycin, enomycin and the tricothecenes.See, for example, WO 93/21232 published Oct. 28, 1993.

Suitable toxins and chemotherapeutic agents are described in REMINGTON'SPHARMACEUTICAL SCIENCES, 19th Ed. (Mack Publishing Co. 1995), and inGOODMAN AND GILMAN'S THE PHARMACOLOGICAL BASIS OF THERAPEUTICS, 7th Ed.(MacMillan Publishing Co. 1985). Other suitable toxins and/orchemotherapeutic agents are known to those of skill in the art.

The anti-CD22 immunotherapy of the present invention may also be inconjunction with a prodrug-activating enzyme which converts a prodrug(e.g., a peptidyl chemotherapeutic agent, see, WO 81/01145) to an activeanti-cancer drug. See, for example, WO 88/07378 and U.S. Pat. No.4,975,278. The enzyme component of such combinations includes any enzymecapable of acting on a prodrug in such a way so as to covert it into itsmore active, cytotoxic form. The term “prodrug” as used in thisapplication refers to a precursor or derivative form of apharmaceutically active substance that is less cytotoxic to tumor cellscompared to the parent drug and is capable of being enzymaticallyactivated or converted into the more active parent form. See, e.g.,Wilman, “Prodrugs in Cancer Chemotherapy” Biochemical SocietyTransactions, 14, pp. 375-382, 615th Meeting Belfast (1986) and Stellaet al., “Prodrugs: A Chemical Approach to Targeted Drug Delivery,”Directed Drug Delivery, Borchardt et al. (ed.), pp. 247-267, HumanaPress (1985). Prodrugs that can be used in combination with theanti-CD22 antibodies of the invention include, but are not limited to,phosphate-containing prodrugs, thiophosphate-containing prodrugs,sulfate-containing prodrugs, peptide-containing prodrugs, D-aminoacid-modified prodrugs, glycosylated prodrugs, α-lactam-containingprodrugs, optionally substituted phenoxyacetamide-containing prodrugs oroptionally substituted phenylacetamide-containing prodrugs,5-fluorocytosine and other 5-fluorouridine prodrugs which can beconverted into the more active cytotoxic free drug. Examples ofcytotoxic drugs that can be derivatized into a prodrug form for use inthis invention include, but are not limited to, those chemotherapeuticagents described above.

In certain embodiments, administration of the compositions and methodsof the invention may enable the postponement of toxic therapy and mayhelp avoid unnecessary side effects and the risks of complicationsassociated with chemotherapy and delay development of resistance tochemotherapy. In certain embodiments, toxic therapies and/or resistanceto toxic therapies is delayed in patients administered the compositionsand methods of the invention delay for up to about 6 months, 1, 2, 3, 4,5, 6, 7, 8, 9, or 10 years.

5.28. Combination with Therapeutic Antibodies

The anti-CD22 immunotherapy described herein may be administered incombination with other antibodies, including, but not limited to,anti-CD20 mAb, anti-CD52 mAb, anti-CD19 antibody (as described, forexample, in U.S. Pat. No. 5,484,892, U.S. patent publication No.2004/0001828 of U.S. application Ser. No. 10/371,797, U.S. patentpublication No. 2003/0202975 of U.S. application Ser. No. 10/372,481 andU.S. provisional application Ser. No. 60/420,472, the entire contents ofeach of which are incorporated by reference herein for their teachingsof CD22 antigens and anti-CD22 antibodies), and anti-CD20 antibodies,such as RITUXAN™ (C2B8; RITUXIMAB™; IDEC Pharmaceuticals). Otherexamples of therapeutic antibodies that can be used in combination withthe antibodies of the invention or used in the compositions of theinvention include, but are not limited to, HERCEPTIN™ (Trastuzumab;Genentech), MYLOTARG™ (Gemtuzumab ozogamicin; Wyeth Pharmaceuticals),CAMPATH™ (Alemtuzumab; Berlex), ZEVALIN™ (Ipritumomab tiuxetan; BiogenIdec), BEXXAR™ (Tositumomab; GlaxoSmithKline Corixa), ERBITUX™(Cetuximab; Imclone), and AVASTIN™ (Bevacizumab; Genentech).

In certain embodiments, the anti-CD22 and anti-CD20 and/or anti-CD52 mAband/or anti-CD19 mAb can be administered, optionally in the samepharmaceutical composition, in any suitable ratio. To illustrate, theratio of the anti-CD22 and anti-CD20 antibody can be a ratio of about1000:1, 500:1, 250:1, 100:1, 90:1, 80:1, 70:1, 60;1, 50:1, 40:1, 30:1.20:1, 19:1, 18:1, 17:1, 16:1, 15:1, 14:1, 13:1, 12:1, 11:1, 10:1,9:1,8:1, 7:1,6:1, 5:1, 4:1, 3:1, 2:1, 1:1, 1:2, 1:3, 1:4, 1:5, 1:6, 1:7,1:8, 1:9, 1:10, 1:11, 1:12, 1:13, 1:14, 1:15, 1:16, 1:17, 1:18, 1:19,1:20, 1:30, 1:40, 1:50, 1:60, 1:70, 1:80, 1:90. 1:100, 1:250, 1:500 or1:1000 or more. Likewise, the ratio of the anti-CD22 and anti-CD52antibody can be a ratio of about 1000:1, 500:1, 250:1, 100:1, 90:1,80:1, 70:1, 60;1, 50:1, 40:1, 30:1. 20:1, 19:1, 18:1, 17:1, 16:1, 15:1,14:1, 13:1, 12:1, 11:1, 10:1, 9:1, 8:1, 7:1, 6:1, 5:1, 4:1, 3:1, 2:1,1:1, 1:2, 1:3, 1:4, 1:5, 1:6, 1:7, 1:8, 1:9, 1:10, 1:11, 1:12, 1:13,1:14, 1:15, 1:16, 1:17, 1:18, 1:19, 1:20, 1:30, 1:40, 1:50, 1:60, 1:70,1:80, 1:90. 1:100, 1:250, 1:500 or 1:1000 or more. Similarly, the ratioof the anti-CD22 and anti-CD19 antibody can be a ratio of about 1000:1,500:1, 250:1, 100:1, 90:1, 80:1, 70:1, 60;1, 50:1, 40:1, 30:1. 20:1,19:1, 18:1, 17:1, 16:1, 15:1, 14:1, 13:1, 12:1, 11:1, 10:1, 9:1,8:1,7:1,6:1, 5:1, 4:1,3:1, 2:1, 1:1, 1:2, 1:3, 1:4, 1:5, 1:6, 1:7, 1:8, 1:9,1:10, 1:11, 1:12, 1:13, 1:14, 1:15, 1:16, 1:17, 1:18, 1:19, 1:20, 1:30,1:40, 1:50, 1:60, 1:70, 1:80, 1:90. 1:100, 1:250, 1:500 or 1:1000 ormore.

5.29. Combination Compounds that Enhance Monocyte or Macrophage Function

In certain embodiments of the methods of the invention, a compound thatenhances monocyte or macrophage function (e.g., at least about 10%, 15%,20%, 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%,90%, 95% or more) can be used in conjunction with the anti-CD22 antibodyimmunotherapy. Such compounds are known in the art and include, withoutlimitation, cytokines such as interleukins (e.g., IL-12), andinterferons (e.g., alpha or gamma interferon).

The compound that enhances monocyte or macrophage function orenhancement can be formulated in the same pharmaceutical composition asthe antibody, immunoconjugate or antigen-binding fragment. Whenadministered separately, the antibody/fragment and the compound can beadministered concurrently (within a period of hours of each other), canbe administered during the same course of therapy, or can beadministered sequentially (i.e., the patient first receives a course ofthe antibody/fragment treatment and then a course of the compound thatenhances macrophage/monocyte function or vice versa). In suchembodiments, the compound that enhances monocyte or macrophage functionis administered to the human subject prior to, concurrently with, orfollowing treatment with other therapeutic regimens and/or thecompositions of the invention. In one embodiment, the human subject hasa blood leukocyte, monocyte, neutrophil, lymphocyte, and/or basophilcount that is within the normal range for humans. Normal ranges forhuman blood leukocytes (total) is about 3,5-about 10.5 (10⁹/L). Normalranges for human blood neutrophils is about 1.7-about 7.0 (10⁹/L),monocytes is about 0.3-about 0.9 (10⁹/L), lymphocytes is about 0.9-about2.9 (10⁹/L), basophils is about 0-about 0.3 (10⁹/L), and eosinophils isabout 0.05-about 0.5 (10⁹/L). In other embodiments, the human subjecthas a blood leukocyte count that is less than the normal range forhumans, for example at least about 0.01, 0.05, 0.1, 0.2, 0.3, 0.4, 0.5,0.6, 0.7, or 0.8 (10⁹/L) leukocytes.

This embodiment of the invention can be practiced with the antibodies,immunoconjugates or antibody fragments of the invention or with otherantibodies known in the art and is particularly suitable for subjectsthat are resistant to anti-CD19, anti-CD52 and/or anti-CD20 antibodytherapy (for example, therapy with existing antibodies such as C2B8),subjects that are currently being or have previously been treated withchemotherapy, subjects that have had a relapse in a B cell disorder,subjects that are immunocompromised, or subjects that otherwise have animpairment in macrophage or monocyte function. The prevalence ofpatients that are resistant to therapy or have a relapse in a B celldisorder may be attributable, at least in part, to an impairment inmacrophage or monocyte function. Thus, the invention provides methods ofenhancing ADCC and/or macrophage and/or monocyte function to be used inconjunction with the methods of administering anti-CD22 antibodies andantigen-binding fragments.

5.30. Combination with Immunoregulatory Agents

The anti-CD22 immunotherapy of the invention of the present inventionmay also be in conjunction with an immunoregulatory agent. In thisapproach, the use of chimerized antibodies is preferred; the use ofhuman or humanized anti-CD22 antibody is most preferred. The term“immunoregulatory agent” as used herein for combination therapy refersto substances that act to suppress, mask, or enhance the immune systemof the host. This would include substances that suppress cytokineproduction, downregulate or suppress self-antigen expression, or maskthe MHC antigens. Examples of such agents include2-amino-6-aryl-5-substituted pyrimidines (see, U.S. Pat. No. 4,665,077),azathioprine (or cyclophosphamide, if there is an adverse reaction toazathioprine); bromocryptine; glutaraldehyde (which masks the MHCantigens, as described in U.S. Pat. No. 4,120,649); anti-idiotypicantibodies for MHC antigens and MHC fragments; cyclosporin A; steroidssuch as glucocorticosteroids, e.g., prednisone, methylprednisolone, anddexamethasone; cytokine or cytokine receptor antagonists includinganti-interferon-γ, -β, or -α antibodies; anti-tumor necrosis factor-αantibodies; anti-tumor necrosis factor-β antibodies; anti-interleukin-2antibodies and anti-IL-2 receptor antibodies; anti-L3T4 antibodies;heterologous anti-lymphocyte globulin; pan-T antibodies, preferablyanti-CD3 or anti-CD4/CD4a antibodies; soluble peptide containing a LFA-3binding domain (WO 90/08187 published Jul. 26, 1990); streptokinase;TGF-β; streptodomase; RNA or DNA from the host; FK506; RS-61443;deoxyspergualin; rapamycin; T-cell receptor (U.S. Pat. No. 5,114,721);T-cell receptor fragments (Offner et al., Science 251:430-432 (1991); WO90/11294; and WO 91/01133); and T-cell receptor antibodies (EP 340,109)such as T10B9. Examples of cytokines include, but are not limited tolymphokines, monokines, and traditional polypeptide hormones. Includedamong the cytokines are growth hormone such as human growth hormone,N-methionyl human growth hormone, and bovine growth hormone; parathyroidhormone; thyroxine; insulin; proinsulin; relaxin; prorelaxin;glycoprotein hormones such as follicle stimulating hormone (FSH),thyroid stimulating hormone (TSH), and luteinizing hormone (LH); hepaticgrowth factor; fibroblast growth factor; prolactin; placental lactogen;tumor necrosis factor-α; mullerian-inhibiting substance; mousegonadotropin-associated peptide; inhibin; activin; vascular endothelialgrowth factor; integrin; thrombopoiotin (TPO); nerve growth factors suchas NGF-α; platelet-growth factor; transforming growth factors (TGFs)such as TGF-α and TGF-α; insulin-like growth factor-I and -II;erythropoietin (EPO); osteoinductive factors; interferons; colonystimulating factors (CSFs) such as macrophage-CSF (M-CSF);granulocyte-macrophage-CgP (GM-CSP); and granulocyte-CSF (G-CSF);interleukins (ILs) such as IL-1, IL-1a, IL-2, IL-3, IL-4, IL-5, IL-6,IL-7, IL-8, IL-9, IL-1 I, IL-12, IL-15; a tumor necrosis factor such asTNF-α or TNF-β; and other polypeptide factors including LIF and kitligand (KL). As used herein, the term cytokine includes proteins fromnatural sources or from recombinant cell culture and biologically activeequivalents of the native sequence cytokines. In certain embodiments,the methods further include administering to the subject one or moreimmunomodulatory agents, preferably a cytokine. Preferred cytokines areselected from the group consisting of interleukin-1 (IL-1), IL-2, IL-3,IL-12, IL-15, IL-18, G-CSF, GM-CSF, thrombopoietin, and γ interferon.

These immunoregulatory agents are administered at the same time or atseparate times from the anti-CD22 antibodies of the invention, and areused at the same or lesser dosages than as set forth in the art. Thepreferred immunoregulatory agent will depend on many factors, includingthe type of disorder being treated, as well as the patient's history,but a general overall preference is that the agent be selected fromcyclosporin A, a glucocorticosteroid (most preferably prednisone ormethylprednisolone), OKT-3 monoclonal antibody, azathioprine,bromocryptine, heterologous anti-lymphocyte globulin, or a mixturethereof.

5.31. Combination with Other Therapeutic Agents

Agents that act on the tumor neovasculature can also be used inconjunction with anti-CD22 immunotherapy and include tubulin-bindingagents such as combrestatin A4 (Griggs et al., Lancet Oncol. 2:82,(2001)) and angiostatin and endostatin (reviewed in Rosen, Oncologist5:20 (2000), incorporated by reference herein). Immunomodulatorssuitable for use in combination with anti-CD22 antibodies include, butare not limited to, of α-interferon, γ-interferon, and tumor necrosisfactor alpha (TNF-α). In certain embodiments, the therapeutic agentsused in combination therapies using the compositions and methods of theinvention are peptides.

In certain embodiments, the anti-CD22 immunotherapy is in conjunctionwith one or more calicheamicin molecules. The calicheamicin family ofantibiotics are capable of producing double-stranded DNA breaks atsub-picomolar concentrations. Structural analogues of calicheamicinwhich may be used include, but are not limited to, γ1¹, γ2¹, γ3¹,N-acetyl-γ1¹, PSAG and 011 Hinman et al., Cancer Research 53:3336-3342(1993) and Lode et al., Cancer Research 58: 2925-2928 (1998)).

Alternatively, a fusion protein comprising an anti-CD22 antibody of theinvention and a cytotoxic agent may be made, e.g., by recombinanttechniques or peptide synthesis.

In yet another embodiment, an anti-CD22 antibody of the invention may beconjugated to a “receptor” (such as streptavidin) for utilization intumor pretargeting wherein the antagonist-receptor conjugate isadministered to the patient, followed by removal of unbound conjugatefrom the circulation using a clearing agent and then administration of a“ligand” (e.g., avidin) which is conjugated to a therapeutic agent(e.g., a radionucleotide).

In certain embodiments, a treatment regimen includes compounds thatmitigate the cytotoxic effects of the anti-CD22 antibody compositions ofthe invention. Such compounds include analgesics (e.g., acetaminophen),bisphosphonates, antihistamines (e.g., chlorpheniramine maleate), andsteroids (e.g., dexamethasone, retinoids, deltoids, betamethasone,cortisol, cortisone, prednisone, dehydrotestosterone, glucocorticoids,mineralocorticoids, estrogen, testosterone, progestins).

In certain embodiments, the therapeutic agent used in combination withthe anti-CD22 immunotherapy of the invention is a small molecule (i.e.,inorganic or organic compounds having a molecular weight of less thanabout 2500 daltons). For example, libraries of small molecules may becommercially obtained from Specs and BioSpecs B.V. (Rijswijk, TheNetherlands), Chembridge Corporation (San Diego, Calif.), Comgenex USAInc. (Princeton, N.J.), and Maybridge Chemicals Ltd. (Cornwall PL34 OHW,United Kingdom).

In certain embodiments the anti-CD22 immunotherapy can be administeredin combination with an anti-bacterial agent. Non-limiting examples ofanti-bacterial agents include proteins, polypeptides, peptides, fusionproteins, antibodies, nucleic acid molecules, organic molecules,inorganic molecules, and small molecules that inhibit and/or reduce abacterial infection, inhibit and/or reduce the replication of bacteria,or inhibit and/or reduce the spread of bacteria to other cells orsubjects. Specific examples of anti-bacterial agents include, but arenot limited to, antibiotics such as penicillin, cephalosporin, imipenem,axtreonam, vancomycin, cycloserine, bacitracin, chloramphenicol,erythromycin, clindamycin, tetracycline, streptomycin, tobramycin,gentamicin, amikacin, kanamycin, neomycin, spectinomycin, trimethoprim,norfloxacin, rifampin, polymyxin, amphotericin B, nystatin,ketocanazole, isoniazid, metronidazole, and pentamidine.

In certain embodiments the anti-CD22 immunotherapy of the invention canbe administered in combination with an anti-fungal agent. Specificexamples of anti-fungal agents include, but are not limited to, azoledrugs (e.g., miconazole, ketoconazole (NIZORAL®), caspofungin acetate(CANCIDAS®), imidazole, triazoles (e.g., fluconazole (DIFLUCAN®)), anditraconazole (SPORANOX®)), polyene (e.g., nystatin, amphotericin B(FUNGIZONE®), amphotericin B lipid complex (“ABLC”) (ABELCET®),amphotericin B colloidal dispersion (“ABCD”) (AMPHOTEC®), liposomalamphotericin B (AMBISONE®)), potassium iodide (KI), pyrimidine (e.g.,flucytosine (ANCOBON®), and voriconazole (VFEND®)). Administration ofanti bacterial and anti-fungal agents can mitigate the effects orescalation of infectious disease that may occur in the methods of theinvention where a patient's B cells are significantly depleted.

In certain embodiments of the invention, the anti-CD22 immunotherapy ofthe invention can be administered in combination with one or more of theagents described above to mitigate the toxic side effects that mayaccompany administration of the compositions of the invention. In otherembodiments, the anti-CD22 immunotherapy of the invention can beadministered in combination with one or more agents that are well knownin the art for use in mitigating the side effects of antibodyadministration, chemotherapy, toxins, or drugs.

In certain embodiments of the invention where the anti-CD22immunotherapy of the invention is administered to treat multiplemyeloma, the compositions of the invention may be administered incombination with or in treatment regimens with high-dose chemotherapy(melphalan, melphalan/prednisone (MP),vincristine/doxorubicin/dexamethasone (VAD), liposomaldoxorubicin/vincristine, dexamethasone (DVd), cyclophosphamide,etoposide/dexamethasone/cytarabine, cisplatin (EDAP)), stem celltransplants (e.g., autologous stem cell transplantation or allogeneicstem cell transplantation, and/or mini-allogeneic (non-myeloablative)stem cell transplantation), radiation therapy, steroids (e.g.,corticosteroids, dexamethasone, thalidomide/dexamethasone, prednisone,melphalan/prednisone), supportive therapy (e.g., bisphosphonates, growthfactors, antibiotics, intravenous immunoglobulin, low-dose radiotherapy,and/or orthopedic interventions), THALOMID™ (thalidomide, Celgene),and/or VELCADE™ (bortezomib, Millennium).

In embodiments of the invention where the anti-CD22 immunotherapy of theinvention are administered in combination with another antibody orantibodies and/or agent, the additional antibody or antibodies and/oragents can be administered in any sequence relative to theadministration of the antibody of this invention. For example, theadditional antibody or antibodies can be administered before,concurrently with, and/or subsequent to administration of the anti-CD22antibody or immunoconjugate of the invention to the human subject. Theadditional antibody or antibodies can be present in the samepharmaceutical composition as the antibody of the invention, and/orpresent in a different pharmaceutical composition. The dose and mode ofadministration of the antibody of this invention and the dose of theadditional antibody or antibodies can be the same or different, inaccordance with any of the teachings of dosage amounts and modes ofadministration as provided in this application and as are well known inthe art.

5.32. Use of Anti-CD22 Antibodies in Diagnosing B Cell Malignancies

The present invention also encompasses anti-CD22 antibodies, andcompositions thereof, that immunospecifically bind to the human CD22antigen, which anti-CD22 antibodies are conjugated to a diagnostic ordetectable agent. In preferred embodiments, the antibodies are human orhumanized anti-CD22 antibodies. Such anti-CD22 antibodies can be usefulfor monitoring or prognosing the development or progression of a B cellmalignancy as part of a clinical testing procedure, such as determiningthe efficacy of a particular therapy. Such diagnosis and detection canbe accomplished by coupling an anti-CD22 antibody thatimmunospecifically binds to the human CD22 antigen to a detectablesubstance including, but not limited to, various enzymes, such as butnot limited to, horseradish peroxidase, alkaline phosphatase,beta-galactosidase, or acetylcholinesterase; prosthetic groups, such asbut not limited to, streptavidin/biotin and avidin/biotin; fluorescentmaterials, such as but not limited to, umbelliferone, fluorescein,fluorescein isothiocynate, rhodamine, dichlorotriazinylaminefluorescein, dansyl chloride or phycoerythrin; luminescent materials,such as but not limited to, luminol; bioluminescent materials, such asbut not limited to, luciferase, luciferin, and aequorin; radioactivematerials, such as but not limited to iodine (¹³¹I, ¹²⁵I, ¹²³I, ¹²¹I),carbon (¹⁴C), sulfur (³⁵S), tritium (³H), indium (¹¹⁵In, ¹¹³In, ¹¹²In,¹¹¹In), and technetium (⁹⁹Tc), thallium (²⁰¹Ti), gallium (⁶⁸Ga, ⁶⁷Ga),palladium (¹⁰³Pd), molybdenum (⁹⁹Mo), xenon (¹³³Xe), fluorine (¹⁸F),¹⁵³Sm, ¹⁷⁷Lu, ¹⁵⁹Gd, ¹⁴⁹Pm, ¹⁴⁰La, ¹⁷⁵Yb, ¹⁶⁶Ho, ⁹⁰Y, ⁴⁷Sc, ¹⁸⁶Re,¹⁸⁸Re, ¹⁴²Pr, ¹⁰⁵Rh, ⁹⁷Ru, ⁶⁸Ge, ⁵⁷Co, ⁶⁵Zn, ⁸⁵Sr, ³²P, ¹⁵³Gd, ¹⁶⁹Yb,⁵¹Cr, ⁵⁴Mn, ⁷⁵Se, ¹¹³Sn, and ¹¹⁷Tin; positron emitting metals usingvarious positron emission tomographies, noradioactive paramagnetic metalions, and molecules that are radiolabelled or conjugated to specificradioisotopes. Any detectable label that can be readily measured can beconjugated to an anti-CD22 antibody and used in diagnosing B cellmalignancies. The detectable substance may be coupled or conjugatedeither directly to an antibody or indirectly, through an intermediate(such as, for example, a linker known in the art) using techniques knownin the art. See, e.g., U.S. Pat. No. 4,741,900 for metal ions which canbe conjugated to antibodies for use as a diagnostics according to thepresent invention. In certain embodiments, the invention provides fordiagnostic kits comprising an anti-CD22 antibody conjugated to adiagnostic or detectable agent.

5.33. Use of Anti-CD22 Antibodies in Monitoring Immune Reconstitution

The present invention also encompasses anti-CD22 antibodies, andcompositions thereof, that immunospecifically bind to the human CD22antigen, which anti-CD22 antibodies are conjugated to a diagnostic ordetectable agent. In preferred embodiments, the antibodies are human orhumanized anti-CD22 antibodies. Such anti-CD22 antibodies can be usefulfor monitoring immune system reconstitution following immunosuppressivetherapy or bone marrow transplantation. Such monitoring can beaccomplished by coupling an anti-CD22 antibody that immunospecificallybinds to the human CD22 antigen to a detectable substance including, butnot limited to, various enzymes, such as, but not limited to,horseradish peroxidase, alkaline phosphatase, beta-galactosidase, oracetylcholinesterase; prosthetic groups, such as, but not limited to,streptavidin/biotin and avidin/biotin; fluorescent materials, such as,but not limited to, umbelliferone, fluorescein, fluoresceinisothiocynate, rhodamine, dichlorotriazinylamine fluorescein, dansylchloride or phycoerythrin; luminescent materials, such as, but notlimited to, luminol; bioluminescent materials, such as, but not limitedto, luciferase, luciferin, and aequorin; radioactive materials, such as,but not limited to, iodine (¹³¹I, ¹²⁵I, ¹²³I, ¹²¹I), carbon (¹⁴C),sulfur (³⁵S), tritium (³H), indium (¹¹⁵In, ¹¹³In, ¹¹²In, ¹¹¹In), andtechnetium (⁹⁹Tc), thallium (²⁰¹Ti), gallium (⁶⁸Ga, ⁶⁷Ga), palladium(¹⁰³Pd), molybdenum (⁹⁹Mo), xenon (¹³³Xe), fluorine (¹⁸F), ¹⁵³Sm, ¹⁷⁷Lu,¹⁵⁹Gd, ¹⁴⁹Pm, ¹⁴⁰La, ¹⁷⁵Yb, ¹⁶⁶Ho, ⁹⁰Y, ⁴⁷Sc, ¹⁸⁶Re, ¹⁸⁸R, ¹⁴²Pr, ¹⁰⁵Rh,⁹⁷Ru, ⁶⁸Ge, ⁵⁷Co, ⁶⁵Zn, ⁸⁵Sr, ³²P, ¹⁵³Gd, ¹⁶⁹Yb, ⁵¹Cr, ⁵⁴Mn, ⁷⁵Se,¹¹³Sn, and ¹¹⁷Tin; positron-emitting metals using variouspositron-emission tomographies, noradioactive paramagnetic metal ions,and molecules that are radiolabelled or conjugated to specificradioisotopes. Any detectable label that can be readily measured can beconjugated to an anti-CD22 antibody and used in diagnosing an autoimmunedisease or disorder. The detectable substance may be coupled orconjugated either directly to an antibody or indirectly, through anintermediate (such as, for example, a linker known in the art) usingtechniques known in the art. See, e.g., U.S. Pat. No. 4,741,900 formetal ions which can be conjugated to antibodies for use as adiagnostics according to the present invention. In certain embodiments,the invention provides for diagnostic kits comprising an anti-CD22antibody conjugated to a diagnostic or detectable agent.

5.34. Use of Anti-CD22 Antibodies in Diagnosing Autoimmune Diseases orDisorders

The present invention also encompasses anti-CD22 antibodies, andcompositions thereof, that immunospecifically bind to the human CD22antigen, which anti-CD22 antibodies are conjugated to a diagnostic ordetectable agent. In preferred embodiments, the antibodies are human orhumanized anti-CD22 antibodies. Such anti-CD22 antibodies can be usefulfor monitoring or prognosing the development or progression of anautoimmune disease or disorder as part of a clinical testing procedure,such as determining the efficacy of a particular therapy. Such diagnosisand detection can be accomplished by coupling an anti-CD22 antibody thatimmunospecifically binds to the human CD22 antigen to a detectablesubstance including, but not limited to, various enzymes, such as butnot limited to, horseradish peroxidase, alkaline phosphatase,beta-galactosidase, or acetylcholinesterase; prosthetic groups, such asbut not limited to, streptavidin/biotin and avidin/biotin; fluorescentmaterials, such as but not limited to, umbelliferone, fluorescein,fluorescein isothiocynate, rhodamine, dichlorotriazinylaminefluorescein, dansyl chloride or phycoerythrin; luminescent materials,such as but not limited to, luminol; bioluminescent materials, such asbut not limited to, luciferase, luciferin, and aequorin; radioactivematerials, such as but not limited to iodine (¹³¹I, ¹²⁵I, ¹²³I, ¹²¹I),carbon (¹⁴C), sulfur (³⁵S), tritium (³H), indium (¹¹⁵In, ¹¹³In, ¹¹²I,¹¹¹In), and technetium (⁹⁹Tc), thallium (²⁰¹Ti), gallium (⁶⁸Ga, ⁶⁷Ga),palladium (¹⁰³Pd), molybdenum (⁹⁹Mo), xenon (¹³³Xe), fluorine (¹⁸F),¹⁵³Sm, ¹⁷⁷Lu, ¹⁵⁹Gd, ¹⁴⁹Pm, ¹⁴⁰La, ¹⁷⁵Y, ¹⁷⁵Yb, ¹⁶⁶Ho, ⁹⁰Y, ⁴⁷Sc, ¹⁸⁶Re,¹⁸⁸Re, ¹⁴²Pr, ¹⁰⁵Rh, ⁹⁷Ru, ⁶⁸Ge, ⁵⁷Co, ⁶⁵Zn, ⁸⁵Sr, ³²P, ¹⁵³Gd, ¹⁶⁹Yb,⁵¹Cr, ⁵⁴Mn, ⁷⁵Se, ¹¹³Sn, and ¹¹⁷Tin; positron emitting metals usingvarious positron emission tomographies, noradioactive paramagnetic metalions, and molecules that are radiolabelled or conjugated to specificradioisotopes. Any detectable label that can be readily measured can beconjugated to an anti-CD22 antibody and used in diagnosing an autoimmunedisease or disorder. The detectable substance may be coupled orconjugated either directly to an antibody or indirectly, through anintermediate (such as, for example, a linker known in the art) usingtechniques known in the art. See, e.g., U.S. Pat. No. 4,741,900 formetal ions which can be conjugated to antibodies for use as adiagnostics according to the present invention. In certain embodiments,the invention provides for diagnostic kits comprising an anti-CD22antibody conjugated to a diagnostic or detectable agent.

5.35. Kits

The invention provides a pharmaceutical pack or kit comprising one ormore containers filled with a composition of the invention for theprevention, treatment, management or amelioration of a B cellmalignancy, or one or more symptoms thereof, potentiated by orpotentiating a B cell malignancy.

The present invention provides kits that can be used in theabove-described methods. In one embodiment, a kit comprises acomposition of the invention, in one or more containers. In anotherembodiment, a kit comprises a composition of the invention, in one ormore containers, and one or more other prophylactic or therapeuticagents useful for the prevention, management or treatment of a B cellmalignancy, or one or more symptoms thereof, potentiated by orpotentiating a B cell malignancy in one or more other containers.Preferably, the kit further comprises instructions for preventing,treating, managing or ameliorating a B cell malignancy, as well as sideeffects and dosage information for method of administration. Optionallyassociated with such container(s) can be a notice in the form prescribedby a governmental agency regulating the manufacture, use or sale ofpharmaceuticals or biological products, which notice reflects approvalby the agency of manufacture, use or sale for human administration.

6. EXAMPLES

The following sections describe the design and construction of achimeric variant of HB22.7 (chHB227) in which the mouse heavy chain andlight chain constant regions have been replaced with human IgGγ1 andIgGκ regions respectively. These sections also describe two strategiesfor generation of humanized variants of HB22.7 heavy and light chainvariable regions which comprise the antibodies of the invention.

The CD22-binding activity of the antibodies produced from variouscombinations of heavy and light chain variable regions is alsodescribed. Humanized forms of HB22.7 which exhibit a CD22 bindingprofile comparable to that of chHB22.7 are described.

The sections below also describe several mutations in the humanframework regions that, when introduced into certain anti-CD22antibodies of the invention, achieve the CD22 binding of the referenceantibody produced by the parental mouse hybridoma, HB22.7. In the VHthese residues are, for example, the Vernier residues N73 and G49, thecanonical residue V24 and a CDR flanking residue S30. In the VK theseare, for example, the VH interaction residue F87 and the CDR-flankingresidues D60 and Y67.

6.1. Gene Assembly

Constructs were generated by a PCR-based gene assembly method firstdescribed by Stemmer (Stemmer, W. P. et al. 1995 Gene, 164:49-53). Thismethod consists of four steps: oligonucleotide synthesis; gene assembly;gene amplification and cloning. Twenty-two 39-mer oligonucleotideprimers were synthesized for each variable region. These primers weredesigned to overlap by 20 nucleotides and were ligated into a completevariable region during thermal cycling. The resulting PCR-products ofthe correct size were cloned into the pCR® 2.1 vector, provided with theTOPO-TA Cloning® kit, and used to transform DH5α competent cellsaccording to the manufacturer's protocols. Colonies containing theplasmid, with a correctly sized insert, were identified by PCR-screeningusing oligonucleotide primers provided with the kit. Plasmid clones,identified with correct sized insert, were sequenced using the ABI Prism310 genetic analyzer. The BigDye® Terminator v3.0 Cycle Sequencing ReadyReaction Kit was used for DNA sequencing according to the manufacturer'sprotocols. Plasmid DNA was prepared from selected clones using theQIAGEN Plasmid Maxi Kit according to the manufacturer's protocols.

Pairs of DNA plasmid expression vector preparations encoding (humanizedor chimeric) heavy and light chains were used to transfect COS-7 cells,by electroporation as described by Kettleborough et al. 1991 ProteinEng., 4:773-783. These transfected COS cells were cultured for 3 days toyield antibody-containing conditioned medium suitable for determiningtotal IgG concentrations and CD22 binding activity.

Total Ig concentrations in the COS cell supernatant were quantifiedusing a capture ELISA assay. IgG molecules were captured on aNunc-Immuno MaxiSorp plate via an immobilized goat anti-human Igγchain-specific antibody, and detected with anti-human kappa light chainHRP-conjugated antibody. The ELISA was calibrated using a reference IgG1mAb of irrelevant specificity. CD22 binding activity was assessed usinga cell-based CD22 ELISA as described in Section 6.2 and was normalizedusing equivalent concentrations of each humanized or chimeric antibody,thereby facilitating direct comparisons between alternative humanizedversions of the HB22.7 antibodies and chHB227

6.2. The BHK-CD22 Binding Assay

The ability of chHB227 and its humanized variants to bind hCD22 wasassessed in a cell based CD22 binding assay utilizing BHK cellsexpressing cell-surface human CD22 as a capture agent. Untransfected BHKcells not expressing hCD22 served as a control for non-specific binding.The BHK and BHK-CD22 lines were grown in DMEM supplemented with 10%Fetal Clone I and antibiotics. G418/Geneticin (0.75 mg/ml) was alsoadded to the growth medium for BHK-CD22 only. The standard NCI protocolwas used for the binding assay.

6.3. Expression Vectors

Plasmid DNA preparations of the expression vectors pKN10 and pG1D20(AERES Biomedical, London) were produced using Qiagen Maxi kitsfollowing the manufacturers protocol to process 500 ml cultures of DH5αbacteria transfected with either vector. This produced 494 micrograms ofpKN10 and 827 micrograms of pG1D20, each in 0.5 ml.

Expression vectors containing HB22.7 heavy and light chain genes weregrown using the same protocol

6.4. Construction, Expression and Binding Characteristics of chHB227

The chHB227 expression vectors were constructed by (1) adding a suitableleader sequence to the VH and VK sequences, preceded by a HindIIIrestriction site and a Kozak sequence; and (2) introducing a 5′ fragmentof the human γ1 constant region, up to a natural ApaI restriction site,contiguous with the 3′ end of the JH region of HB22.7 for the VHsequences and, for the VK sequence, adding a splice donor site and BamHIsite.

The Kozak consensus sequence is used to obtain efficient translation ofa variable region sequence. It defines the correct AUG codon from whicha ribosome can commence translation. The mouse VH leader sequence(MUSIGHXL (SEQ ID NO:68) from the PCG1-1 VH gene, (Stenzel-Poore, M. P.,et al 1987. J. Immunol. 139 (5), 1698-1703) and the mouse VK leadersequence (SK/CamRK) (SEQ ID NO:71) were selected based on their naturalassociation with VH and VK genes that share high sequence homology withthe mouse VH and VK expressed in HB22.7. Forward primers were designedto incorporate these leader sequences into the appropriate constructs.The splice donor sequence is important for the correct in-frameattachment of the variable region to its appropriate constant region,thus splicing out the V:C intron. The intron and CH are encoded in theexpression vector downstream of the HB22.7 VH sequence.

The HB22.7 VH and VK genes were first carefully analyzed to identify anyunwanted splice donor sites, splice acceptor sites, Kozak sequences andfor the presence of any extra sub-cloning restriction sites which wouldlater interfere with the subcloning and/or expression of functionalwhole antibody. In this case none were found.

6.4.1. The Light Chain Chimerization Primers

The region of the HB22.7 kappa chain leader sequence outside the primersite was used to search a database of mouse immunoglobulin leadersequences. A match was found with both SK/CamRK and BALB/c VkSer leadersequences. Primers were designed to generate a PCR product containingthe complete SK/CamRK leader, and the HB22.7 VL region, with terminalrestriction sites Hind III and Bam HI for cloning into the pKN10expression vector. The forward primers introduced a Hind III restrictionsite; a Kozak translation initiation site and the SK/CamRKimmunoglobulin leader sequence. The back primers introduced a splicedonor site and a Bam HI restriction site.

6.4.2. The Heavy Chain Chimerization Primers

The region of the HB22.7 heavy chain leader sequence outside the primersite was used to search a database of mouse immunoglobulin leadersequences. A single match was found with MUSIGHXL also known as PCG1-1VH (GenBank M17774) Primers were designed to generate a PCR productcontaining this complete leader, and the HB22.7 variable region, withterminal restriction sites and Hind III and Apa I for cloning into thepG1D20 expression vector. The forward primers introduced a Hind IIIrestriction site, a Kozak translation initiation site, and the PCG1-1immunoglobulin leader sequence. The back primers introduced the 5′ endof the γ1 C region and a natural Apa I restriction site.

6.4.3. Generation of the chHB22.7Hc Heavy Chain Expression Construct

The HB22.7 VH clone S51/1 was amplified with VH Forward and VH Backprimers in a polymerase chain reaction using ADVANTAGE®-HF 2 DNApolymerase. The 400 bp PCR product was cut with HindIII and Apa I andligated into the vector pG1D20 (FIGS. 1A and 1B). Chemically competentDH5α bacteria were transformed with the ligation product. Clones wereisolated and selected for the appearance of a 400 bp insert released byHindIII+Apa I digestion of individual plasmid preps. Selected plasmidswere sequenced in both directions. The clone S76/12 was chosen after thesequence was confirmed in both directions as corresponding to thepredicted sequence of the modified HB22.7 heavy chain. This clone wasgrown in 500 ml culture to produce 0.7 mg of plasmid DNA using theQiagen Maxi Kit using the manufacturer's protocol.

6.4.4. Generation of the chHB22.7Kc Light Chain Expression Construct

The HB22.7 VK clone S36/5 was amplified with VK Forward and VK Backprimers in a polymerase chain reaction using ADVANTAGE®-HF 2 DNApolymerase. The 400 bp PCR product was cut with Bam HI and Hind III andligated into the vector pKN10 (FIGS. 2A and 2B). Chemically competentDH5α bacteria were transformed with the ligation product. Clones wereisolated and selected for the appearance of a 400 bp insert released byBam HI+Hind III digestion of individual plasmid preps. Selected plasmidswere sequenced in both directions. The clone S67/7 was chosen after thesequence was confirmed in both directions as corresponding to thepredicted sequence of the modified HB22.7 light chain. This clone wasgrown in 500 ml culture to produce 0.54 mg of plasmid DNA using theQiagen Maxi Kit using the manufacturers protocol.

6.4.5. Production and Binding Properties of chHB22.7 Antibody

COS 7 cells were cultured in DMEM supplemented with 10% Fetal Clone Iand antibiotics. One week later, cells (0.7 ml at 10⁷/ml) wereelectroporated with the chimeric heavy and light chain expressionplasmids (10 μg DNA each) or no DNA. The cells were plated in 8 ml ofgrowth medium and cultured for 3 days.

6.4.6. Chimeric Antibody Production

A sandwich ELISA was used to measure antibody concentrations in the COS7 supernatants. The transiently transformed COS 7 cells secreted asignificant level of IgG1-kappa antibody, e.g., 916.4±83.2 and1554.4±146 ng/ml.

6.4.7. Chimeric Antibody Activity

The BHK-CD22 binding assay was used to test the binding activity of thechHB227 antibody in the transiently transformed COS 7 culturesupernatants. A goat anti-human Ig-HRP conjugate (Sigma Chemicals) wasused to detect binding of chHB22.7 mAb while a goat anti-mouse Ig-HRPconjugate (Southern Biotechnology) was used to detect binding of theparental mouse HB22.7 mAb. The bound HRP conjugates were exposed to thesubstrate o-phenyldiamine (OPD) and the resulting products detected at450 nm. As shown in FIG. 3, the binding of the parental mouse antibodyproduced by HB22.7 and the novel chHB227 antibody were found to becomparable. For concentrations of antibody above 100 ng/ml, there was asignificant specific binding of both mouse and chimeric antibody toCD22, indicating that the chHB22.7 has retained CD22 binding activity.

6.5. Identification of Human Acceptor Framework Regions

The protein sequences of human and mouse immunoglobulins from TheInternational Immunogenetics Database (2003) and the last availabledownloadable Kabat Database of Sequences of Proteins of ImmunologicalInterest (1997) were used to compile a database of immunoglobulinprotein sequences in Kabat alignment. This database contains 45,948files. The sequence analysis program, SR v7.6, was used together withthe Perl script program, Autohum, to query the human VH and human VKdatabases with the mouse antibody HB227 VH and VK protein sequences, SEQID NO:7 (VH) and SEQ ID NO:27 (VK) respectively.

The antibody structures from Protein Data Bank (PDB), release 103(2003), (Berman H. M. et al., (2000) The Protein Data Bank. NucleicAcids Res. 28, 235-242) were compiled into a sequence databasecontaining 378 heavy and 378 light chain structures, which was queriedwith the mouse antibody HB227 VH and VK protein sequences, SEQ ID NO:7(VH) and SEQ ID NO:27 (VK). The pair of heavy and light chains havingthe best overall sequence homology to HB22.7 was found in the 43C9antibody (Thayer, M. M. et al. (1999) J Mol. Biol. 291, 329-345).

The program AbM was used to generate the molecular model of HB22.7 mouseantibody based on the antibody 43C9 heavy and light chain structures.The canonical structure of HB22.7 was used to select VH and VL CDRstructures within the molecular modeling program, and to assist in theselection of human acceptor sequences with similar canonical structures.HB227 VH framework region residues predicted to have a packinginteraction with the CDR, by virtue of being within 200% van der Waal'sradius of a CDR atom, are indicated with asterisks as shown in FIG. 4.These framework positions in the humanized VH can be changed back to thecorresponding residue in the VH of the mouse antibody HB22.7 (a processreferred to herein as “backmutation”), according to methods known in theart.

6.5.1. Selection of a Human Variable Heavy Chain Framework for CDRGrafting

The nearest mouse germline gene to HB227 VH is V00767. The mutationsfrom that germline sequence which are present in HB22.7 VH may relate tothe binding specificity and/or affinity of HB22.7 antibody for humanCD22. The HB227 VH framework region was compared with the human VHdatabase. Among the 20 human VH sequences with high Vernier andframework homology to the mouse HB227 VH, seven were selected forfurther analyses (V46898, V46897, AY190826, AB066856, P2, OU, andCLL-11). These VH regions were determined not to be of mouse origin,humanized, or from a scFv library. VH 46897, had 63/87 identities in theframework region; CLL-11, had 62/87 identities in the framework region;and 46898, had 61/87 identities in the framework region. Each of thesethree antibodies had two Vernier mismatches, i.e., 14/16 Vernierresidues are shared with the HB22.7 heavy chain. VH 46897 has anadditional disadvantage of a mismatched Vernier residue at position 71,which is a glutamine instead of lysine. This mismatch is not present inthe next four high-scoring candidate VH sequences, CLL-11, 46898,AY190826, and AB066856. Each of these four candidates also has aconservative substitution of alanine for the glycine at Vernier position49, i.e., they each have the point mutation G49A compared to the HB227VH sequence. VH 46898 also has a conservative substitution of argininefor the lysine at position 81 in FW 3, i.e., it contains the pointmutation K81R compared to the HB227 VH sequence. The candidate VHsequences CLL-11, AY190826, and AB066856 have a nonconservativesubstitution of threonine for the lysine at this position, whilecandidate sequence 46897 has a serine at this position. The candidate VHsequences 46898, AY190826, and AB066856 also contain non-HB22.7 residuesat positions 24 and 49.

Sequence VH 46898 (SEQ ID NO:6) was chosen as an acceptor frameworkregion for the humanization of the HB227 VH. This antibody is a humananti-RSV antibody designated RF-2 and is derived from SCID miceimplanted with human spleen cells (Heard C. et al. (1999) Twoneutralizing human anti-RSV antibodies: cloning, expression, andcharacterization. Mol. Med. 5, 35-45).

6.5.2. Generation of HB22.7RHB

At the protein level, the humanization of HB227 VH required grafting theCDRs from the HB22.7 VH into the published VH 46898 framework amino acidsequence to generate the humanized HB227RHB construct depicted in FIGS.5A and 5B. However, because the VH 46898 was not available as a nucleicacid sequence, the nearest germline VH genes, V2-70 and IC4 were used toderive the desired VH 46898 framework acceptor sequence. The acceptornucleotide sequence was generated by mutation of the DNA sequence ofVH2-70, combined with the framework 4 region of antibody IC4 (FIGS. 5Aand 5B). The CDR DNA sequences of HB227 VH were combined with theframework DNA sequences of the newly created 46898 to generate themature framework and CDR coding sequence (FIGS. 5A and 5B). As shown inFIGS. 5C and 5D, the resulting construct was further modified byreplacing VH2-70 and IC4 codons and individual nucleotides with commoncodons needed to generate a VH 46898 nucleic acid sequence. To allowefficient expression of this sequence, a leader sequence from thenearest germline gene VH2-05 (FIGS. 5C and 5D) was positioned upstreamof the VH construct. The VH2-50 leader was used because there is nopublished leader for VH2-70. The resulting humanized sequence with theVH2-50 leader sequence was named HB227RHB (SEQ ID NO:16 and 17) (FIGS.5C and 5D).

Several variants of HB227RHB were generated by backmutating specificmismatched Vernier residues at positions 49 and 73 (FIGS. 5E and 5F).The resulting sequences, HB227RHC (SEQ ID NO:18 and 19), HB227RHD (SEQID NO:20 and 21) and HB227RHE (SEQ ID NO:22 and 23) are depicted inFIGS. 5E and 5F.

Inspection of the Vernier and canonical residues in the humanized VH,HB227RHC, indicated that only one of these residues, canonical residueF24, is not identical with the corresponding mouse residue (see FIGS. 5Eand 5G). Accordingly, the next version of the humanized VH, HB227RHF,was designed to change the canonical residue F24 to V24. HB227RHF wasgenerated from HB227RHC by mutating F24V using a mutagenesis kit (FIGS.5E and 5G).

6.5.3. Selection of a Human Variable Light Chain Framework for CDRGrafting

The HB22.7 VK FW region was compared with the human VK database. Themost closely related mouse germline gene is AJ235968. Somatic mutationspresent in the HB227 VK sequence may suggest critical residues for thespecificity or affinity of the HB22.7 antibody for human CD22. FIG. 6identifies the Vernier, Canonical, Interface residues and those residuespredicted to be within the 200% van der Waal's radii (200% VdW) from aCDR atom in the AbM model of HB22.7 antibody. Twenty human VK sequenceswith the highest Vernier and FW homology to the HB22.7 VK sequence wereselected from the available human VK sequences. Of the high FW homologyscoring human light chains, all matched the mouse Vernier positions(FIG. 6) and two were neither mouse nor recombinant. These were AJ388641and VL clone 47. These sequences have similar FW regions except for twoimportant differences. First, the AJ388641 sequence contains twonon-conservative substitutions compared with the HB22.7 VK sequence. Thefirst is a substitution of Glutamine for Valine at position 3 and thesecond is a substitution of Glutamine for Glycine at position 100.Accordingly, the VL clone 47 sequence was chosen as the candidate humanacceptor sequence for humanizing HB227 VK. The nearest human germlinegene for the human acceptor sequence, VL clone 47 is DPK018. The nearestgermline JK gene is JK2.

6.5.3.1. Generation of HB22.7RKA

The generation of the humanized variant of HB22.7 VK, HB227RKA is shownin FIG. 7A-B. Because the desired kappa acceptor sequence, VL clone 47was available only as a protein sequence (Welschof M. et al. (1995) JImmunol Methods 179, 203-214), a closely related available VL sequence,AJ388641, was mutated to generate the VL clone 47 sequence as shown inFIGS. 7A and 7B. The leader sequence from the germline human VK gene,DPK018 (FIGS. 7C and 7D), was attached to the mature HB227RKA to yieldthe complete HB22.7RKA sequence shown in FIGS. 7C and 7D.

Inspection of the Vernier, canonical and VH interaction residues (“VCI”residues) in the humanized VK, HB227RKA (SEQ ID NO:34 and 35), indicatedthat only one residue was different from the mouse sequence, theVH-interface residue Y87 (FIGS. 7C and 7D). Accordingly, a new versionof HB227RKA having the point mutation Y87F was constructed anddesignated HB227RKB (SEQ ID NO:36 and 37). However, the CD22 bindingaffinity of antibodies comprising HB227RKB was markedly less than thatobserved with the chHB22.7 mAb (FIG. 8). Accordingly, the model of themouse HB22.7 Fv was examined in an effort to identify additional lightchain residues that may influence binding. The model suggested thebackmutations S60D and S67Y because these residues may participate inthe antigen-antibody interface. Accordingly, these backmutations wereintroduced into HB22.7RKB to create HB227RKC (SEQ ID NO:38 and 39). Theaspartic residue at 60 and the tyrosine at position 67 introduced intoHB227RKC are found in the HB227 VK sequence (SEQ ID NO:26 and 27).

6.6. hCD22 Binding Characteristics of Antibodies Derived fromTransiently Expressed Humanized HB22.7 VH and VK Sequences.

The VK versions HB227RKA, HB227RKB, and HB227RKC were expressed incombination with chimeric or humanized variable heavy chain sequences.The binding of the resulting antibodies to hCD22 is shown in FIG. 8.Antibodies comprising either HB227RHB or HB227RHC paired with HB227RKAdid not effectively bind to hCD22 expressed on BHK cells. However, eachVH and VK chain separately combined with its cognate chimeric light orheavy chain showed significant binding. The combination of the chimericlight chain with HB227RHC bound CD22 about two-fold better than with thesame chimeric light chain associated with HB227RHB.

The CD22 binding of the HB227RHF+chL combination was comparable to thatof the chHB227 antibody indicating that back mutation of canonicalresidue 24 is a beneficial step in the humanization of HB227 VH (FIG. 9)Successive increases in binding effectiveness from HB227RKA to HB227RKBto HB227RKC were observed when each light chain variant was combinedwith HB227RHF (FIG. 9), indicating that these VK mutations are providingimportant structural features and that the CDR-flanking non-VCIresidues, D60 and Y67, are important for antigen binding. The RHF+RKCbinding curve overlies the CH+CK fully chimeric binding curve,indicating that this humanized antibody (HB227RHF+HB227RKC) has CD22binding activity similar to that of the chimeric antibody.

To confirm the binding effectiveness of the RHF+RKC humanized antibody,a competitive ELISA was performed with increasing amounts of the mouseHB22.7 antibody mixed with 250 ng/ml of chimeric or humanized antibody.FIG. 10 shows that the IC₅₀ for both the chimeric and the humanizedantibody was about 4 μg/ml, indicating that the CD22 binding affinity ofthe humanized antibody is comparable to that of the chimeric antibody.

The CD22 binding assay was further used to demonstrate that HB227RKC incombination with HB227RHF resulted in an antibody with enhanced bindingactivity over the HB227RKC with either HB227 RHB or HB227RHC (FIG. 10).The improved binding of RHF results from the canonical F24V mutation andnot the VL-interface mismatches at VH residues 37 and 91 that had littleeffect on binding (FIG. 11). Therefore back mutation of these residuesis not necessary for binding to CD22.

6.7. Selection of an Alternative VH Framework for CDR Grafting Based onConserved Vernier, Canonical, and Interface Residues Between HB227VH anda Human Acceptor VH.

A molecular model of HB22.7 mouse antibody was used to determine thoseframework residues which are in a 200% van der Waal's (“VdW”) envelopearound the CDRs. These are framework amino acid residues containing anatom whose center is within 200% of its van der Waal's radius from theouter electron shell of an atom contained in a CDR residue, as describedby Winter in U.S. Pat. No. 6,548,640. FIG. 12 shows these residues alongwith the Vernier, canonical, and interface residues. The VdW radii usedwere from L1, A. J. and R. Nussinov (1998) Proteins 32:111-127. Eightresidues are not back-mutable because they lie outside the area definedby the 200% VdW envelope. Those VCI residues which are not in thisenvelope are the following: three canonicals, V24, G26, F27; oneVernier, N73; and the VL interaction residues V37, Q39, L45, and Y91.All other Vernier and canonical residues are positioned within the 200%VdW envelope.

The eight important VCI residues (V24, G26, F27, N73, V37, Q39, L45, andY91) outside the VdW envelope were subsequently used to search the humanVH sequence databases for VH regions encoding these residues at thespecified positions. Among the approximately 2500 VH sequences analyzed,VCI positions 27, 37 and 91 were frequently conserved (FIG. 16).However, there were only 19 Vh sequences that matched at 4 of the 5residues: 24; 26; 39; 45 and 73, and had fewer than 55 matchingframework residues after back mutation of 4 framework residues (F29L,D30S, T49G, and F67L). Of these 19 sequences, 14 matching at frameworkposition 73 were selected for further study. Eight of these 14 sequenceshave Pro or Cys residues at unusual positions, rendering them lessacceptable as an acceptor sequence. A final shortlist of five human VHsequences was identified (FIG. 17). The AJ556657, AB067248, AJ556642,AJ556644, and AF376954 VH sequences shared 63.2%, 67.8%, 64.4%, 64.4%and 65.6% identity, respectively, with the FW of the parental mouseHB22.7 VH after backmutation of the four FW residues (F29L, D30S, T49G,and F67L) that fall within the 200% VdW envelope (FIGS. 12, 13A and13B). From this data and close inspection of each framework position ineach candidate framework acceptor, the AJ556657 VH (SEQ ID NO:40 and 41)(see Colombo, M. M. et al. (2003) Eur. J. Immunol. 33:3433-3438) waschosen as the alternative human VH acceptor.

6.8. Generation of Alternative Humanized Variant of HB227 VH

The strategy used for grafting the HB227 VH CDRs onto the human AJ556657framework regions (SEQ ID NO:40 and 41) is shown if FIG. 13A-D. TheHB227-AJ556657 (SEQ ID NO:42 and 43) protein sequence was furthermodified by introducing back mutations (F29L, D30S, T49G, and F67L) thatfall within the 200% VdW envelope. The resulting protein sequence,HB227RHO, (SEQ ID NO:46 and 47) is shown in FIGS. 13C and 13D.

The signal sequence from the most homologous germline gene to AJ556657,VH 3-30, was assessed for the correct scission site when used with FW1from AJ556657. Using a the signal protease algorithm (see Nielsen, H. J.et al. (1997) Protein Eng. 10:1-6), the VH3-30 leader sequence was foundto predict the correct scission site, confirming that the VH 3-30 leaderis an appropriate choice for RHO. The DNA and protein sequence of RHOwith the VH 3-30 leader sequence are shown in FIGS. 13C and D. For thisgene assembly only, we used an offline program for generating the DNAsequence directly from the protein sequence known as DNA Works (seeHoover, D. M. and J. Lubkowski (2002) Nucleic Acids Res. 30:e43) whichis designed to use high abundance human codons.

6.9. FACS Analyses of the Binding of HB227RHO+HB227RKC Antibody to hCD22Expressed on BHK Cells.

The HB227RHO heavy chain was expressed along with the HB227RKC lightchain and tested for CD22 binding. As shown in FIG. 11, the binding ofHB227RHO is better than HB227RHC and similar to that observed withHB227RHF. Thus, the RHO heavy chain represents a functional low sequenceidentity alternative to the RHF heavy chain. It should be pointed outthat RHO-mediated binding is achieved despite the presence of 6mismatched vernier, 1 mismatched canonical, and 1 mismatched VLinteraction residues i.e. 8 VCI residues are mismatched in RHO, but eachof these mismatches is conservative in the AJ556657 acceptor framework.The mismatch at canonical residue 24, which was shown to be important inHB227RHF, was a non-conservative mismatch, whereas in HB227RHO, therewas a conservative mismatch, which has less impact on binding.

6.10. Generation and Expression of RHOv2 by Backmutation of Residueswithin the 200% VdW Envelope Around the HB227 VH CDRs.

Critical framework residues within the 200% VdW envelope around the CDRsaccording to the molecular model which can be backmutated are F29; D30;T49; and F67. These four positions were backmutated to generate the RHOsequence and codon optimization was used to generate RHOv2 as shown inFIGS. 13C and 13D. The leader sequence of the VH2-05 gene was appendedto the RHOv2 sequence. The codon usage of RHOv2 differs from that of RHOin that it is from the natural sequences, while for RHO, the codons weregenerated by the computer program DNA Works.

As shown in FIG. 14A, HB227RHOv2 VH in combination with HB227RKC VKresulted in an antibody that bound hCD22. To determine which of thebackmutated residues were important for binding activity, the F29L;D30S; T49G; and F67L mutations were individually reversed to generateHB227v2A (SEQ ID NO:50 and 51), HB227v2B (SEQ ID NO:52 and 53), HB227v2C(SEQ ID NO:54 and 55), and HB227v2D (SEQ ID NO:56 and 57) (FIG. 13E-G).

COS cell transfections with each HB227RHOv2 variant in combination withthe HB227RKC VK yielded antibodies that bound BHK-hCD22 expressing cellswith differing intensities (FIGS. 14A-14E). Human CD22 binding wasadversely affected by reversing the D30S backmutation (i.e. introducingan aspartic residue at position 30) as was done in HB227RHOv2B.Therefore, the mouse Serine 30 residue is important for strong bindingbut the Leu29, Gly 49 and Leu67 can be replaced by the correspondingamino acids in human AJ556657 sequence without significantlycompromising binding.

In an effort to reduce the number of backmutations, the HB227RHOv2A VHwas further mutated so as to re-insert the corresponding human residuesat positions 49 and 67 (tyrosine and phenylalanine respectively). Theresulting construct, RHOv2ACD (SEQ ID NO:58 and 59) is shown in FIGS.13E and 13G along with a construct, HB227RHOv2ABCD (SEQ ID NO:60 and 61)in which all four backmutations were reversed (FIGS. 13E and 13G). Asshown in FIGS. 15A, 15B and 15D, the HB227RHOv2ACD VH in combinationwith either HB227RKA or HB227RKC VK yields an antibody that binds hCD22similarly to that of the HB227RHF VH in combination with HB227RKC. TheHB227RHOv2ABCD VH yielded a hCD22 binding antibody when associated withthe HB227RKC VK (FIG. 15E) but binding was significantly compromisedwhen the same VH was associated with the HB227RKA light chain. (FIG.15C).

Taken together, these data indicate that a number of humanized versionsof the HB22.7 VH and VK chains were created that retain the bindingproperties of the parental mouse antibody derived from the HB22.7hybridoma.

6.10.1. Antibodies and Immunofluorescence Analysis

The anti-CD22 antibodies described above, which bind to the human CD22antigen, can be used in the approaches disclosed below. Otherantibodies, which could be employed in the experiments described belowinclude monoclonal mouse anti-CD19 antibodies that bind to mouse CD19,e.g. MB19-1 (IgA) (Sato et al., J. Immunol., 157:4371-4378 (1996));monoclonal mouse CD20-specific antibodies (Uchida et al., Intl.Immunol., 16:119-129 (2004)); B220 antibody RA3-6B2 (DNAX Corp., PaloAlto, Calif.); and CD5, CD43 and CD25 antibodies (BD PHARMINGEN™,Franklin Lakes, N.J.). Isotype-specific and anti-mouse Ig or IgMantibodies can be obtained from Southern Biotechnology Associates, Inc.(Birmingham, Ala.).

Either mouse pre-B cell lines, transfected with hCD22 cDNA, which can bedeveloped using methods and materials known in the art (see e.g. Alt etal., Cell, 27:381-388 (1981) and Tedder and Isaacs, J. Immunol.,143:712-717 (1989)), or single-cell leukocyte suspension, are stained onice using predetermined, optimal concentrations of eachfluorescently-labeled antibody for 20-30 minutes according toestablished methods (Zhou et al., Mol. Cell. Biol., 14:3884-3894(1994)). Cells with the forward and side light scatter properties oflymphocytes can then be analyzed on FACSCAN® or FACSCALIBUR® flowcytometers (Becton Dickinson, San Jose, Calif.). Background stainingwould be determined using unreactive control antibodies (CALTAG™Laboratories, Burlingame, Calif.) with gates positioned to excludenonviable cells. For each sample examined, ten thousand cells with theforward and side light scatter properties of mononuclear cells areanalyzed whenever possible, with fluorescence intensities shown on afour-decade log scale.

Mice. Transgenic mice expressing hCD22 and their wild-type (WT)littermates can be produced as described in the art (Zhou et al., Mol.Cell. Biol., 14:3884-3894 (1994)). For example, hCD22tg mice can begenerated from original hCD22 founders (e.g. C57BL/6×B6/SJL), and thencrossed onto a C57BL/6 background for at least 7 generations. hCD22tgmice would be generated from original hCD22 founders (e.g.C57BL/6×B6/SJL). After multiple generations of backcrossing, mice wouldbe obtained in which their B cells would express cell surface density ofhuman CD22 at about the same density found on human B cells.

Mice bred with FcR (Fc receptor) common γ chain (FcRγ)-deficient mice(FcRγ^(−/−), B6.129P2-Fcerg1^(tml)) are available from Taconic Farms(Germantown, N.Y.) and could be used to generate hCD22^(+/−) FcRγ^(−/−)and WT littermates. Mice hemizygous for a c-Myc transgene (Eμ-cMycTG,C57B1/6J-TgN(IghMyc); The Jackson Laboratory, Bar Harbor, Me.) aredescribed in the art (Harris et al., J. Exp. Med., 167:353 (1988) andAdams et al., Nature, 318:533 (1985)). c-MycTG mice (B6/129 background)could be crossed with hCD22tg mice to generate hemizygous hCD22tgcMycTG^(+/−) offspring that could be identified by PCR screening.Rag1^(−/−) (B6.129S7-Rag1^(tm1Mom)/J) mice are available from TheJackson Laboratory. Macrophage-deficient mice can be generated by tailvein injections of clodronate-encapsulated liposomes (0.1 mL/10 grambody weight; Sigma Chemical Co., St. Louis, Mo.) into C57BL/6 mice onday −2, 1 and 4 in accordance with standard methods (Van Rooijen andSanders, J. Immunol. Methods, 174:83-93 (1994)). All mice should behoused in a specific pathogen-free barrier facility and first used at6-9 weeks of age.

ELISAs. Serum Ig concentrations are determined by ELISA usingaffinity-purified mouse IgM, IgG1, IgG2a, IgG2b, IgG3, and IgA (SouthernBiotechnology Associates, Inc., Birmingham, Ala.) to generate standardcurves as described (Engel et al., Immunity, 3:39 (1995)). Serum IgM andIgG autoantibody levels against dsDNA, ssDNA and histone are determinedby ELISA using calf thymus double-stranded (ds) DNA (Sigma-Aldrich, St.Louis, Mo.), boiled calf thymus DNA (which contains single-stranded (ss)DNA) or histone (Sigma-Aldrich) coated microtiter plates as described(Sato et al., J. Immunol., 157:4371 (1996)).

Immunotherapy. Sterile anti-CD22 and unreactive, isotype controlantibodies (0.5-250 μg) in 200 μL phosphate-buffered saline (PBS) areinjected through lateral tail veins. For example, experiments would usea fixed amount (e.g. 250 μg) of antibody. Blood leukocyte numbers arequantified by hemocytometer following red cell lysis, B220+B cellfrequencies are determined by immunofluorescence staining with flowcytometry analysis. Antibody doses in humans and mice would be comparedusing the Oncology Tool Dose Calculator(www.fda.gov/cder/cancer/animalframe.htm).

Immunizations. Two-month old WT mice are immunized i.p. with 50 μg of2,4,6-trinitrophenyl (TNP)-conjugated lipopolysaccharide (LPS) (Sigma,St. Louis, Mo.) or 25 μg 2,4-dinitrophenol-conjugated (DNP)-FICOLL®(Biosearch Technologies, San Rafael, Calif.) in saline. Mice are alsoimmunized i.p. with 100 μg of DNP-conjugated keyhole limpet hemocyanin(DNP-KLH, CALBIOCHEM®-NOVABIOCHEM® Corp., La Jolla, Calif.) in completeFreund's adjuvant and are boosted 21 days later with DNP-KLH inincomplete Freund's adjuvant. Mice are bled before and afterimmunizations as indicated. DNP- or TNP-specific antibody titers inindividual serum samples are measured in duplicate using ELISA platescoated with DNP-BSA (CALBIOCHEM®-NOVABIOCHEM® Corp., La Jolla, Calif.)or TNP-BSA (Biosearch Technologies, San Rafael, Calif.) according tostandard methods (Engel et al., Immunity, 3:39-50 (1995)). Sera fromTNP-LPS immunized mice are diluted 1:400, with sera from DNP-FICOLL® andDNP-BSA immunized mice diluted 1:1000 for ELISA analysis.

Statistical Analysis. All data would be shown as means±SEM withStudent's t-test used to determine the significance of differencesbetween sample means

6.10.2.1 Human CD22 Expression in Transgenic Mice

Transgenic hCD22tg mice, which can be developed as described herein, orother transgenic animals expressing human CD22 can be used to assessdifferent therapeutic regimens comprising the anti-CD22 antibodies ofthe invention, such as variations in dosing concentration, amount, andtiming. The efficacy in human patients of different therapeutic regimenscan be predicted using the two indicators described below, i.e., B celldepletion in certain bodily fluids and/or tissues and the ability of amonoclonal human or humanized anti-CD22 antibody to bind B cells. Inparticular embodiments, treatment regimens that are effective in humanCD22 transgenic mice could be used with the compositions and methods ofthe invention to treat autoimmune diseases or disorders in humans.

In order to determine whether human CD22 is expressed on B cells fromtransgenic mice (hCD22tg) expressing the human CD22 transgene, B cellswould be extracted from the bone marrow, blood, spleen and peritoneallavage of these mice. Human CD22 and mouse CD22 expression would beassessed in these cells by contacting the cells with anti-CD22antibodies that bind CD22. Binding of the antibody to the B lineagecells would be detected using two-color immunofluorescence staining withflow cytometry analysis. The relative expression levels of mCD22 andhCD22, would be assessed by measuring mean fluorescence intensity(anti-hCD22 for hCD22 and anti-mCD22 for mCD22) respectively.

6.10.3. Anti-CD22 Antibody Depletion of B Cells In Vivo

The anti-CD22 antibodies of the invention, which bind to human CD22, canbe assessed for their ability to deplete hCD22tg blood, spleen, andlymph node B cells in vivo. For example, each antibody would be given tomice at either 250 or 50 μg/mouse, a single dose about 10 to 50-foldlower than the 375 mg/m² dose primarily given four times for anti-CD20therapy in humans (Maloney et al., J. Clin. Oncol., 15:3266-74 (1997)and McLaughlin et al., Clinical status and optimal use of rituximab forB cell lymphomas, Oncology (Williston Park), 12:1763-9 (1998)). B celldepletion from blood, spleen and lymph nodes of hCD22tg mice would bedetermined by immunofluorescence staining with flow cytometry analysis.The results using anti-CD22 antibodies identified as capable ofdepleting B cells can be correlated to use in humans and antibodies withproperties of the identified antibodies can be used in the compositionsand methods of the invention for the treatment of autoimmune diseasesand disorders in humans.

6.10.4. CD22 Density Influences the Effectiveness of CD22Antibody-Induced B Cell Depletion

To determine whether an anti-CD22 antibody's ability to deplete B cellsis dependent on CD22 density, anti-CD22 antibodies of the invention canbe administered to mice having varying levels of hCD22 expression. Theresults obtained will demonstrate that human CD22 density on B cells andantibody isotype can influence the depletion of B cells in the presenceof an anti-CD22 antibody. The same assay can be used to determinewhether other anti-CD22 antibodies can effectively deplete B cells andthe results can be correlated to treatment of human patients withvarying levels of CD22 expression. Thus, the methods for examining CD22presence and density, described herein, can be used in human subjects toidentify patients or patient populations for which certain anti-CD22antibodies can deplete B cells and/or to determine suitable dosages.

To determine whether CD22 density influences the effectiveness ofanti-CD22 antibody-induced B cell depletion representative blood andspleen B cell depletion can be examined in hCD22tg mice after treatmentwith the anti-CD22 antibodies of the invention (7 days, 250 μg/mouse).The results are expected to demonstrate that CD22 density influences theefficiency of B cell depletion by anti-CD22 antibodies in vivo. Forexample, low-level CD22 expression in hCD22tg mice would be expected tohave a marked influence on circulating or tissue B cell depletion by theadministered antibody. B cell clearance can be assessed 24 hours afteranti-CD22 or control mAb treatment of individual mice.

6.10.5. Tissue B Cell Depletion is Not Expected to be FcγR-Dependent

Should administration of an anti-CD22 mAb of the invention result intissue B cell depletion, the following assays can be used to demonstratedependence upon FcγR expression. Through a process of interbreedinghCD22tg mice with mice lacking expression of certain FcγR, mice can begenerated that express hCD22 and lack expression of certain FcγR. Suchmice can be used in assays to assess the ability of anti-CD22 antibodiesto deplete B cells through pathways that involve FcγR expression, e.g.,ADCC. Thus, anti-CD22 antibodies identified in these assays can be usedto engineer chimeric, human or humanized anti-CD22 antibodies using thetechniques described above. Such antibodies can in turn be used in thecompositions and methods of the invention for the treatment ofautoimmune diseases and disorders in humans.

The innate immune system mediates B cell depletion following anti-CD20antibody treatment through FcγR-dependent processes. Mouse effectorcells express four different FcγR classes for IgG, the high-affinityFcγRI (CD64), and the low-affinity FcγRII (CD32), FcγRIII (CD16), andFcγRIV molecules. FcγRI, FcγRIII and FcγRIV are hetero-oligomericcomplexes in which the respective ligand-binding a chains associate witha common γ chain (FcRγ). FcRγ chain expression is required for FcγRassembly and for FcγR triggering of effector functions, includingphagocytosis by macrophages. Since FcRγ^(−/−) mice lack high-affinityFcγRI (CD64) and low-affinity FcγRIII (CD16) and FcγRIV molecules,FcRγ^(−/−) mice expressing hCD22 can be used to assess the role of FcγRin tissue B cell depletion following anti-CD22 antibody treatment.

6.10.6. Durability of Anti-CD22 Antibody-Induced B Cell Depletion

To assess the efficacy and duration of B cell depletion, hCD22tg micecan be administered a single low dose (e.g. 250 μg) injection ofanti-CD22 antibody and the duration and dose response of B celldepletion followed as a function of time. The results are expected todemonstrate that circulating B cells are depleted for a substantialamount of time (e.g. one week to six months), followed by a gradualrecovery of blood-borne B cells.

6.10.7. Persistence of CD22 on the Surface of B Cells AfterAdministration of Anti-CD22 Antibody

Whether CD22 internalization will influence B cell depletion in vivo canbe assessed by comparing cell-surface CD22 expression followingadministration of the anti-CD22 antibodies of the present invention (250μg). For example, cell surface CD22 expression and B cell clearance inhCD22tg mice treated with an anti-CD22 antibody of the present inventionor isotype-matched control antibody (250 μg) in vivo can be studied as afunction of time. Thus, spleen B cells can be harvested and assayed forCD22 at time zero (prior to anti-CD22 administration), and at 1, 4, and24 hours post-antibody administration. Isolated B cells may also betreated in vitro with saturating concentrations of each anti-CD22antibody plus isotype-specific secondary antibody in vitro with flowcytometry analysis to visualize total cell surface CD22 expression.Where CD22 on the surface of B cells is maintained, it will indicatecontinued susceptibility to ADCC, CDC, and/or apoptosis. If CD22persists on the cell surface following binding of an anti-CD22 antibody,the B cell will remain accessible to the ADCC, CDC, and/or apoptoticactivity. Such results would demonstrate, in part, why the anti-CD22antibodies and treatment regimens of the invention will be efficaciousin providing therapy for transplantation and treating autoimmunediseases and disorders.

6.10.8. Anti-CD22 Antibody Treatment Will Abrogate Humoral Immunity andAutoimmunity

In the event CD22 therapy decreases B cell representation, then theassays described in this example can be used to demonstrate that theanti-CD22 antibodies of the invention are capable of eliminating orattenuating immune responses. These assays can also be used to identifyother anti-CD22 antibodies that can be used to engineer chimeric, humanor humanized anti-CD22 antibodies using the techniques described above.Such antibodies can in turn be used in the compositions and methods ofthe invention for the treatment of autoimmune disease and disorders inhumans, as well as for transplantation therapy.

The effect of anti-CD22 antibody-induced B cell depletion on serumantibody levels can be assessed by giving hCD22tg mice a singleinjection of anti-CD22 antibody and then assessing the reduction inimmunoglobulin levels in those mice. For example, two-month-oldlittermates can be treated with a single injection of an anti-CD22antibody of the present invention or a control antibody (e.g. 250 μg) onday 0. Antibody levels are then determined by ELISA. It is expected thatthe results will show that after 1 to 2 weeks, serum IgM, IgG2b, IgG3,and IgA antibody levels are significantly reduced, and remain reducedfor at least 10 weeks.

Since hCD22tg mice are expected to produce detectable autoantibodiesafter 2 months of age (Sato et al., J. Immunol., 157:4371 (1996)), serumautoantibody binding to ssDNA, dsDNA and histones may also be assessed.It is expected that anti-CD22 antibody treatment will reduceautoantibody anti-dsDNA, anti-ssDNA and anti-histone autoantibody levelsafter anti-CD22 antibody treatment; it is expected that anti-CD22antibody treatment will significantly reduce serum IgM autoantibodylevels after 2 weeks and prevent the generation of isotype-switched IgGautoantibodies for up to 10 weeks. Accordingly, B cell depletion willsubstantially reduce acute and long-term antibody responses andattenuate class-switching of normal and pathogenic immune responses.

The influence of B cell depletion on T cell-independent type 1 (TI-1)and type 2 (TI-2) antibody responses may also be assessed by immunizinghCD22tg mice with TNP-LPS or DNP-Ficoll (at day zero), 7 days afteranti-CD22 antibody or control antibody treatment. Significanthapten-specific IgM, IgG, and IgA antibody responses are expected not tobe observed in anti-CD22 antibody-treated mice immunized with eitherantigen. Antibody responses to the T cell-dependent (TD) Ag, DNP-KLH,may also be assessed using mice treated with anti-CD22 antibody 7 daysbefore immunization, where it is expected that DNP-KLH immunized micetreated with anti-CD22 antibody will show reduced humoral immunity.

6.10.9. Anti-CD22 Antibody Treatment in Conjunction with Anti-CD20Antibody Treatment

The assay described herein can be used to determine whether othercombination therapies, e.g., anti-CD22 antibodies in combination withchemotherapy, toxin therapy or radiotherapy, have beneficial effects,such as an additive or more that additive depletion in B cells. Theresults of combination therapies tested in animal models can becorrelated to humans by means well-known in the art.

Anti-CD20 antibodies are effective in depleting human and mouse B cellsin vivo. Therefore, the benefit of simultaneous treatment with ananti-CD22 antibody of the present invention and anti-CD20 (MB20-11)antibodies can be assessed to determine whether this will enhance B celldepletion. Mice can be treated with suboptimal doses (e.g. 2 μg, 5 μg,10 μg, 20 μg, or 50 μg) of each antibody either individually, or as acombination of both antibodies. It is expected that the results willdemonstrate that simultaneous anti-CD22 and anti-CD20 antibodytreatments are beneficial. In a similar manner, the efficacy may bedetermine for treatment with a combination of an anti-CD22 antibody ofthe present invention with an anti-CD19 antibody, or a combination of ananti-CD22 antibody of the present invention, an anti-CD19 antibody, andan anti-CD20 antibody.

6.10.10. Therapeutic Efficacy of Subcutaneous (S.C.) Administration ofan Anti-CD22 Antibody of the Invention

The assay described herein can be used to determine whether asubcutaneous route of administration of an anti-CD22 antibody of theinvention can effectively deplete B cells. The results of the efficacyof different delivery routes tested in animal models can be correlatedto humans by means well-known in the art.

For example, hCD22tg mice can be treated with an anti-CD22 antibody ofthe invention at 250 μg either by subcutaneous (s.c.), intraperitoneal(i.p.) or intravenous (i.v.) administration. Values are determined forthe mean (±SEM) blood (per mL), bone marrow, spleen, lymph node, andperitoneal cavity B220⁺ B cell numbers on day seven as assessed usingflow cytometry. Results are expected to demonstrate that subcutaneous(s.c.), intraperitoneal (i.p.) and intravenous (i.v.) administration ofan anti-CD22 antibody of the invention will effectively depletecirculating and tissue B cells in vivo.

6.10.11. Binding Affinity of Murine Antibody HB22.7 and HumanizedAntibody RHOv2ACD/RKA

Binding affinity of HB22.7 and RHOv2ACD/RKA were determined on a BIAcore3000 instrument (BIAcore, Inc., Uppsala, Sweden). The ligand, hCD22, wasprepared at 50 nM in 10 mM NaOAc, pH4 buffer. It was injected onto anEDC/NHS-activated CM5 sensor chip (BIAcore, Inc. Uppsala, Sweden) usinga standard immobilization protocol. Following this, any unreacted activeester moieties were quenched using 1M Et-NH2 (ethanolamine; couplingreagents purchased from BIAcore, Inc.). A total of 535 and 689 RUs hCD22remained bound to two sensor chip surfaces used in these experiments.Separately, a blank surface was prepared on each sensor chip using theidentical protocol (minus protein). The blank surfaces were used as areference cell in the experiments, and served to correct for bothnon-specific binding and some housekeeping artifacts.

For the kinetic experiments, HB22.7 and RHOv2ACD/RKA were prepared astwo dilution series, starting at 22 nM and 100 nM, then diluted three-and two-fold, respectively, down to final concentrations of 0.03 nM and0.39 nM in HBS-EP buffer (BIAcore, Inc., consisting of the following: 10mM HEPES buffer, pH7.4, 150 mM NaCl, 3 mM EDTA, and 0.005% P20). Eachconcentration of IgG was then injected over both the CD22 and referencecell surfaces, which are connected in series. Between injections,surfaces were regenerated with a 1-minute injection of 3M MgCl2.

Raw binding data was corrected in the manner described by Myszka (D. G.Myszka, Improving biosensor analysis. J. Mol. Recognit. 12 (1999), pp.279-284). Fully corrected binding data was then globally fit using a 1:1binding model (BIAevaluation 4.1 software, BIAcore, Inc, Uppsala,Sweden) to obtain the rate and apparent binding constants. The affinitydeterminations for the HB22.7 and RHOv2ACD/RKA antibodies are asfollows:

k_(on) k_(off) K_(D) (M-1s-1) (s-1) (nM) HB22.7 1.2 × 104 1.7 × 10−4 14RHOv2ACD/RKA 3.2 × 104 6.9 × 10−4 226.10.12. Murine Antibody HB22.7 and Humanized Antibody RHOv2ACD/RKA Bindto COS Cells Transfected to Express hCD22

CHO cells expressing hCD22 were prepared by transfection with a plasmidencoding human CD22 using the Lipofectamine procedure. Two dayspost-transfection, both transfected and non-transfected cells wereharvested, resuspended in PBS at a concentration of 1×10⁶/ml and stainedwith antibodies over a range of 0.0625 μg antibody/10⁶ cells to 10 μgantibody/10⁶ cells. Cells were incubated on ice for 20 minutes thenwashed and resuspended in PBS followed by addition of secondaryantibody, either a goat anti-human (GAH) or GAM-F(ab)′2 anti human-RPEat a 1:1000 dilution. Cells were incubated on ice for an additional 10minutes and binding activity was evaluated via FACS analysis on a Guavaflow cytometer. FIG. 18 shows the median fluorescence intensity (MFI)caused by binding of HB22.7 and RHOv2ACD/RKA to hCD22 expressing CHOcells.

6.10.13. Murine Antibody HB22.7 and Humanized Antibody RHOv2ACD/RKA Bindto Daudi Cells

Humanized RHOvACD/RKA and murine HB22.7 anti-hCD22 mAbs were labeledwith Alexa-fluor 488. The Alexa-fluor (AF) labeled antibodies wereseparately incubated with Daudi cells that had been prepared at aconcentration of 1×10⁶ cells/ml. Briefly, Daudi cells were incubated onice for 20 minutes with either of the HB22.7 or RHOv2ACD/RKA antibodiesat a microgram amount ranging from 0 to 5 per 1×10⁶ cells. After 20minute incubations on ice, cells were washed, resuspended in PBS andanalyzed by FACS on a Guava flow cytometer. FIG. 19 provides the FACSanalysis of binding of each of the HB22.7 and RHOv2ACD antibodies toDaudi cells.

6.10.14. Anti-hCD22 Antibodies HB22.7 and RHOv2ACD/RKA PromoteInternalization of CD22

Anti-hCD22 antibodies HB22.7 and RHOv2ACD/RKA were labeled with the pHinsensitive fluorophore Alexa Fluor-647. B cells (Daudi, humantonsillar, or human peripheral blood) were stained with 10 μg/ml of theAlexa Fluor-647 labeled anti-hCD22 mAbs or left in medium alone for 20minutes on ice. Cells were then incubated with antibody or medium alonefor up to 2 hours. The cells were harvested and washed in ice-coldstaining buffer and either fixed or stripped with an acidic solution(PBS containing 30 mM sucrose, pH 2.5) for 45 seconds on ice, washed incomplete media and resuspended in staining-fixative buffer. CD22expression (total and internalized) was assessed by flow cytometry. Thedata provided in each of FIGS. 20-22 are depicted both as the totalantibody binding activity (a) and as percentage of internalized(acid-resistant fluoro-labeled) mAb (b). FIG. 20 provides this data fortotal antibody binding and percentage internalization on Daudi cells.FIG. 21 provides this data for total antibody binding and percentageinternalization on human magnetic cell sorted (MACS)-enriched tonsillarB cells. FIG. 22 provides this data for total antibody binding andpercentage internalization on human MACS-enriched peripheral blood Bcells.

6.10.15. Comparison of CD22 Internalization with Blocking, HB22.7 andRHOv2ACD/RKA, Versus Non-Blocking, HB22.15, Anti-hCD22 Antibodies

Anti-hCD22 antibodies HB22.7, RHOv2ACD/RKA, and HB22.15 were eachlabeled with Alexa Fluor-647. Daudi cells were stained with 10 μg/ml ofeach of the Alexa Fluor-647 labeled anti-hCD22 mAbs or left in mediumalone for 20 minutes on ice. Cells were then incubated with antibody ormedium alone for up to 2 hours. The cells were harvested and washed inice-cold staining buffer and either fixed or stripped with an acidicsolution (PBS containing 30 mM sucrose, pH 2.5) for 45 seconds on ice,washed in complete media and resuspended in staining-fixative buffer.CD22 expression was assessed by flow cytometry. FIG. 23 shows that eachof the anti-hCD22 antibodies, HB22.7, RHOv2ACD/RKA, and HB22.15, wasinternalized by the Daudi cells. Non-ligand blocking anti-hCD22antibody, HB22.15 mediated faster antigen internalization relative toligand blocking anti-hCD22 antibodies HB22.7 and RHOv2ACD/RKA on Daudicells.

6.10.16. ADCC Effector Function of Anti-hCD22 RHOv2ACD/RKA Antibody

Antibodies Rituxan and RHOv2ACD/RKA were each diluted from 0.1 ng/ml to10 μg/ml in media and transferred to a 96 well plate. Target cells, Rajicells, at a concentration of 0.4×10⁶/ml were added to each well followedby effector cells, KC1333 at a concentration of 1×10⁶/ml (for a ratio of1:2.5 target (Raji):effector (KC1333) cells). Proper controls such astarget cells only, effector cells only, and target cells only with andwithout lysis buffer were also included. After a 3 hour incubation at 37C, lysis buffer was added to appropriate control wells and the 96 wellplate was returned to the incubator for an additional hour. After the 4hour total incubation period, the plate was centrifuged, a sample of thesupernatant was removed from each well, and the sample transferred to anew 96 well dish. The LDH assay was performed using the Promeganon-radioactive cytotoxicity assay as outlined in the kit protocol. FIG.24 provides the ADCC effector function mediated by each of the Rituxanand RHOv2ACD/RKA antibodies.

6.10.17. CDC Effector Function of Anti-hCD22 RHOv2ACD/RKA Antibody

Antibodies Rituxan and RHOv2ACD/RKA were each diluted from 0.1 ng/ml to10 μg/ml in either RPMI Phenol Free media containing 10% heatinactivated or untreated human serum and transferred to a 96 well plate.Target cells, Raji cells, at a concentration of 0.4×10⁶/ml and effectorcells, KC1333 at a concentration of 1×10⁶/ml were also prepared in RPMIPhenol Free medium containing either 10% heat inactivated or untreatedhuman serum. Appropriate target cells were added to each well containingantibody, followed by appropriate effector cells. Proper controls suchas target cells only, effector cells only, and target cells only withand without lysis buffer were also included. After a 3 hour incubationat 37 C, lysis buffer was added to appropriate control wells and the 96well plate was returned to the incubator for an additional hour. Afterthe 4 hour total incubation period, the plate was centrifuged, a sampleof the supernatant was removed from each well, and the sampletransferred to a new 96 well dish. The LDH assay performed using thePromega non-radioactive cytotoxicity assay as outlined in the kitprotocol. FIG. 25 provides the CDC effector function mediated by each ofthe Rituxan and RHOv2ACD/RKA antibodies. Fresh donor serum was thesource of complement for this Example, HI indicates use of heatinactivated serum.

6.10.18. HB22.7 and RHOv2ACD/RKA Antibodies Interfere with Daudi CellAdhesion to hCD22-Expressing COS Cells

COS cells were transfected with a hCD22 encoding plasmid using theLipofectamine procedure. Two days post-transfection, both transfectedand non-transfected COS cells were harvested. Transfection efficiencywas evaluated by incubating transfected cells with murine and human CD22antibodies.

Once binding to the transfected COS cells was established, thetransfected COS cells were incubated with either no antibody or murineHB22.7 or humanized RHOv2ACD-RKA CD22 antibodies at 10 μg/ml for 30minutes on ice. The cells were washed with media. Daudi cells were thenadded to all wells and the wells were incubated for an additional 30minutes on ice. Again, the cells were washed with media, formalin fixedand the images photographed. FIG. 26 shows that while Daudi cells didnot adhere to the non-transfected COS cells (A), Daudi cells clusteredwith the COS cells transfected with the hCD22-encoding plasmid (B).Incubation of the COS cells transfected with the hCD22-encoding plasmidwith either HB22.7 (C) or RHOv2ACD/RKA (D) interfered with adhesion ofDaudi cells.

6.10.19. Effect of RHOv2ACD/RKA Antibody on Anti-CD22 Signaling Activity

Ramos B cell lymphoma were suspended in DPBS containing 3% FBS (stainingbuffer) at 10×10⁷ cells/ml. The cells were loaded for 40 minutes at 37°C. with 1 μM of Fluor-4 ester, washed and resuspended in staining bufferat 2×10⁶ cells/ml. Prior to FACS analysis, the cells were incubated for10 minutes at 37° C., followed by addition of increasing concentrationsof either anti-IgM (FIG. 27A) or the indicated concentrations of antih-CD22 RHOv2ACD/RKA mAb (FIG. 27B). Baseline emission fluorescence wascollected for 30 seconds before the addition of F(ab′)₂ anti-IgM (0.5μg/ml to 10 μg/ml) or RHOv2ACD/RKA (2.5 μg/ml to 10 μg/ml). Increases ofcalcium mobilization are represented as increase of fluorescenceintensity after anti-IgM relative to the fluorescence intensity ofuntreated cells. Similar results to those observed for RHOv2ACD/RKA wereobtained for HB22.7.

6.10.20. Anti-IgM-Induced Ca-flux is Enhanced by Ligand Blocking hCD22Antibodies, HB22.7 and RHOv2ACD/RKA

MACS-enriched human peripheral blood B cells were suspended in DPBScontaining 3% FBS (staining buffer) at 10×10⁷ cells/ml. The cells wereloaded for 40 minutes at 37° C. with 1 μM of Fluor-4 ester, washed andresuspended in staining buffer at 2×10⁶ cells/ml. Prior to FACSanalysis, the cells were incubated for 15 minutes at 37° C., followed byaddition of the indicated anti hCD22 mAbs (HB22.7, RHOv2ACD/RHO, andHB22.15) for 5 minutes. Baseline emission fluorescence was collected for30 seconds before the addition of F(ab′)₂ anti-IgM (10 μg/ml). Increasesof calcium mobilization are represented as increased fluorescenceintensity after either anti hCD22 alone or anti hCD22 followed byanti-IgM relative to the fluorescence intensity of untreated cells. Itcan be seen in both FIGS. 28A and 28B that Ca-flux in cells treated withboth a hCD22 ligand blocking antibody (either RHOACD/RKA (28A) or HB22.7(28B)) and anti-IgM is greater than with anti-IgM alone. Neither anisotype control (IC) antibody R347 (FIG. 28A) nor a non-ligand blocking(NLB) antibody HB22.15 (FIG. 28B) enhanced anti-IgM Ca-flux in the humanperipheral B cells.

6.10.21. Effect of HB22.7 and RHOv2ACD/RKA on Ramos Cell Survival

Ramos B cell lymphoma (4×10⁵/ml) were incubated at 37° C. with 10 μg/mlof anti h-CD22 mAbs (RHOv2ACD/RKA and HB22.7) or isotype control (R347)(not shown) for 15 minutes followed by addition of F(ab′)₂ anti-IgM (3.3μg/ml and 10 μg/ml) or complete media as indicated. Cells were culturedfor 48 hours, washed twice with cold DPBS, and analyzed by flowcytometry on a FACSCalibur. The gated live cells (FSC right gates) wasconfirmed by staining the cells with Annexin V-APC and propidium iodide(PI) according to the manufacturer's protocol (BD) (live cells appearedas Annexin V and PI double negative population, not shown). Treatment ofRamos B cells was as follows: (A) no antibody; (B) 10 μg/ml HB22.7; (C)10 μg/ml RHOv2ACD/RKA; (D) 3.3 μg/ml anti-IgM; (E) 3.3 μg/ml anti-IgM+10μg/ml HB22.7; (F) 3.3 μg/ml anti-IgM+10 μg/ml RHOv2ACD/RKA; (G) 10 μg/mlanti-IgM; (H) 10 μg/ml anti-IgM+10 μg/ml HB22.7.

6.10.22. Dissociation of HB22.7 and RHOv2ACD Antibodies from Daudi Cells

Daudi lymphoma B cells were stained for 20 minutes on ice withfluorescence-labeled anti h-CD22 mAbs (10 μg/ml). The cells were thenwashed and resuspended in complete medium at 5×10⁶ cells/ml. Cells wereincubated at indicated times at 37° C. or left on ice, washed andresuspended in staining buffer-containing fixative followed by flowcytometry analysis. FIG. 30 provides the dissociation of the antibodiesfrom Daudi cells over 2 hr. The RHOv2ACD/RKA antibody may have a higherdissociate rate than HB22.7 from Daudi cells, which correlates to itslower affinity to CD22 on these cells.

The present invention is not to be limited in scope by the specificembodiments described herein. Indeed, various modifications of theinvention in addition to those described will become apparent to thoseskilled in the art from the foregoing description and accompanyingfigures. Such modifications are intended to fall within the scope of theappended claims.

Various publications are cited herein, the disclosures of which areincorporated by reference in their entireties.

1-17. (canceled)
 18. A method of treating a B cell malignancy in ahuman, comprising administering to a human in need thereof atherapeutically-effective amount of a humanized anti-CD22 monoclonalantibody comprising a heavy chain and a light chain, wherein the heavychain variable region (“VH”) comprises three complementarity determiningregions, VH CDR1, VH CDR2, and VH CDR3, and four framework regions, VHFW1, VH FW2, VH FW3, and VH FW4, in the order VH FW1-VH CDR1-VH FW2-VHCDR2-VH FW3-VH CDR3-VH FW4; wherein VH CDR1 comprises the amino acidsequence DYGVN (SEQ ID NO:62), VH CDR2 comprises the amino acid sequenceIIWGDGRTDYNSALKS (SEQ ID NO:63), and VH CDR3 comprises the amino acidsequence APGNRAMEY (SEQ ID NO:64); wherein the light chain variableregion (“VK”) comprises three complementarity determining regions, VKCDR1, VK CDR2, and VK CDR3, wherein VK CDR1 comprises the amino acidsequence KASQSVTNDVA (SEQ ID NO:65), VK CDR2 comprises the amino acidsequence YASNRYT (SEQ ID NO:66), and VK CDR3 comprises the amino acidsequence QQDYRSPWT (SEQ ID NO:67), and wherein (i) VH FW1 comprises theamino acid sequence QVQLEESGGGVVRPGRSLRLSCAASGFTFS (SEQ ID NO:81); or(ii) VH FW1 comprises the amino acid sequenceQVQLEESGGGVVRPGRSLRLSCAASGFTLD (SEQ ID NO:82); or (iii) VH FW1 comprisesthe amino acid sequence QVQLEESGGGVVRPGRSLRLSCAASGFTLS (SEQ ID NO:83)and VH FW2 comprises the amino acid sequence WIRQAPGKGLEWVT (SEQ IDNO:84); or (iv) VH FW1 comprises the amino acid sequenceQVQLEESGGGVVRPGRSLRLSCAASGFTLS (SEQ ID NO:83) and VH FW3 comprises theamino acid sequence RFTVSRNNSNNTLSLQMNSLTTEDTAVYYCVR (SEQ ID NO:86). 19.(canceled)
 20. (canceled)
 21. The method of claim 18, wherein the VH FW2of the humanized anti-CD22 monoclonal antibody comprises the amino acidsequence WIRQAPGKGLEWVT (SEQ ID NO:84).
 22. The method of claim 18,wherein the VH FW3 of the humanized anti-CD22 monoclonal antibodycomprises the amino acid sequence RFTVSRNNSNNTLSLQMNSLTTEDTAVYYCVR (SEQID NO:86).
 23. The method of claim 18, wherein the VH FW4 of thehumanized anti-CD22 monoclonal antibody comprises the amino acidsequence WGQGVLVTVS (SEQ ID NO:88).
 24. The method of claim 18, whereinVH FW1 comprises the amino acid sequence QVQLEESGGGVVRPGRSLRLSCAASGFTFS(SEQ ID NO:81), VH FW2 comprises the amino acid sequence WIRQAPGKGLEWVT(SEQ ID NO:84), VH FW3 comprises the amino acid sequenceRFTVSRNNSNNTLSLQMNSLTTEDTAVYYCVR (SEQ ID NO:86), and VH FW4 comprisesthe amino acid sequence WGQGVLVTVS (SEQ ID NO:88).
 25. The method ofclaim 18, wherein VH FW2 of the humanized anti-CD22 monoclonal antibodycomprises the amino acid sequence WIRQAPGKGLEWVG (SEQ ID NO:85), andwherein (i) VH FW1 comprises the amino acid sequenceQVQLEESGGGVVRPGRSLRLSCAASGFTFS (SEQ ID NO:81); or (ii) VH FW1 comprisesthe amino acid sequence QVQLEESGGGVVRPGRSLRLSCAASGFTLD (SEQ ID NO:82);or (iii) VH FW1 comprises the amino acid sequenceQVQLEESGGGVVRPGRSLRLSCAASGFTLS (SEQ ID NO:83) and VH FW3 comprises theamino acid sequence RFTVSRNNSNNTLSLQMNSLTTEDTAVYYCVR (SEQ ID NO:86). 26.The method of claim 18, wherein the VH FW3 of the humanized anti-CD22monoclonal antibody comprises the amino acid sequenceRLTVSRNNSNNTLSLQMNSLTTEDTAVYYCVR (SEQ ID NO:87), and wherein (i) VH FW1comprises the amino acid sequence QVQLEESGGGVVRPGRSLRLSCAASGFTFS (SEQ IDNO:81); or (ii) VH FW1 comprises the amino acid sequenceQVQLEESGGGVVRPGRSLRLSCAASGFTLD (SEQ ID NO:82); or (iii) VH FW1 comprisesthe amino acid sequence QVQLEESGGGVVRPGRSLRLSCAASGFTLS (SEQ ID NO:83)and VH FW2 comprises the amino acid sequence WIRQAPGKGLEWVT (SEQ IDNO:84).
 27. The method of claim 18, wherein the VH comprises the aminoacid sequence of SEQ ID NO:
 59. 28. The method of claim 24, wherein theVK comprises four framework regions, VK FW1, VK FW2, VK FW3, and VK FW4,in the order VK FW1-VK CDR1—VK FW2-VK CDR2—VK FW3-VK CDR3-VK FW4;wherein VK FW1 comprises the amino acid sequence DIVMTQSPSSLSASVGDRVTITC(SEQ ID NO:117), VK FW2 comprises the amino acid sequenceWYQQKPGKAPKLLIY (SEQ ID NO:118), VK FW3 comprises the amino acidsequence GVPSRFSGSGSGTDFTLTISSLQPEDFATYYC (SEQ ID NO:119) orGVPDRFSGSGYGTDFTLTISSLQPEDFATYFC (SEQ ID NO:126), and VK FW4 comprisesthe amino acid sequence FGGGTKVEIKRT (SEQ ID NO:127).
 29. Apolynucleotide molecule comprising a nucleic acid sequence encoding theamino acid sequence of SEQ ID NO: 51, SEQ ID NO: 53, SEQ ID NO: 55, SEQID NO: 57, or SEQ ID NO:
 59. 30. The polynucleotide molecule of claim29, wherein the nucleic acid sequence is SEQ ID NO:
 58. 31. Thepolynucleotide molecule of claim 29, wherein the nucleic acid sequenceencodes the amino acid sequence of SEQ ID NO:
 59. 32. The polynucleotidemolecule of claim 31, which comprises a nucleic acid sequence of ahumanized anti-CD22 heavy chain variable region encoded by a plasmiddeposited with the American Type Culture Collection having accessiondeposit no. PTA-7373.
 33. A vector comprising the polynucleotidemolecule of claim
 31. 34. A mammalian cell comprising the vector ofclaim 33.